<?php
/**
 * iCalcreator, the PHP class package managing iCal (rfc2445/rfc5445) calendar information.
 *
 * copyright (c) 2007-2019 Kjell-Inge Gustafsson, kigkonsult, All rights reserved
 * Link      https://kigkonsult.se
 * Package   iCalcreator
 * Version   2.26.8
 * License   Subject matter of licence is the software iCalcreator.
 *           The above copyright, link, package and version notices,
 *           this licence notice and the invariant [rfc5545] PRODID result use
 *           as implemented and invoked in iCalcreator shall be included in
 *           all copies or substantial portions of the iCalcreator.
 *
 *           iCalcreator is free software: you can redistribute it and/or modify
 *           it under the terms of the GNU Lesser General Public License as published
 *           by the Free Software Foundation, either version 3 of the License,
 *           or (at your option) any later version.
 *
 *           iCalcreator is distributed in the hope that it will be useful,
 *           but WITHOUT ANY WARRANTY; without even the implied warranty of
 *           MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *           GNU Lesser General Public License for more details.
 *
 *           You should have received a copy of the GNU Lesser General Public License
 *           along with iCalcreator. If not, see <https://www.gnu.org/licenses/>.
 *
 * This file is a part of iCalcreator.
*/

namespace Kigkonsult\Icalcreator\Util;

use Kigkonsult\Icalcreator\IcalInterface;
use Kigkonsult\Icalcreator\Vcalendar;
use DateTimeZone;
use DateTime;
use Exception;

use function array_change_key_case;
use function array_filter;
use function array_merge;
use function array_slice;
use function bin2hex;
use function checkdate;
use function count;
use function ctype_digit;
use function date;
use function explode;
use function floor;
use function gmdate;
use function in_array;
use function is_array;
use function is_null;
use function key;
use function ksort;
use function microtime;
use function mktime;
use function openssl_random_pseudo_bytes;
use function ord;
use function rtrim;
use function sprintf;
use function str_replace;
use function strcasecmp;
use function strlen;
use function strpos;
use function strtolower;
use function strtoupper;
use function substr;
use function substr_count;
use function time;
use function trim;
use function ucfirst;

/**
 * iCalcreator utility/support class
 *
 * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
 * @since  2.26.9 - 2019-04-09
 */
class Util implements IcalInterface
{

    /**
     * @var string  some common X-properties
     * @see http://en.wikipedia.org/wiki/ICalendar#Calendar_extensions
     * @static
     */
    public static $X_WR_CALNAME    = 'X-WR-CALNAME';
    public static $X_WR_CALDESC    = 'X-WR-CALDESC';
    public static $X_WR_RELCALID   = 'X-WR-RELCALID';
    public static $X_WR_TIMEZONE   = 'X-WR-TIMEZONE';
    public static $X_LIC_LOCATION  = 'X-LIC-LOCATION';

    /**
     * @var string  iCal property names
     * @static
     */
    public static $ACTION           = 'ACTION';
    public static $ATTACH           = 'ATTACH';
    public static $ATTENDEE         = 'ATTENDEE';
    public static $CALSCALE         = 'CALSCALE';
    public static $CATEGORIES       = 'CATEGORIES';
    public static $CLASS            = 'CLASS';
    public static $COMMENT          = 'COMMENT';
    public static $COMPLETED        = 'COMPLETED';
    public static $CONTACT          = 'CONTACT';
    public static $CREATED          = 'CREATED';
    public static $DESCRIPTION      = 'DESCRIPTION';
    public static $DTEND            = 'DTEND';
    public static $DTSTAMP          = 'DTSTAMP';
    public static $DTSTART          = 'DTSTART';
    public static $DUE              = 'DUE';
    public static $DURATION         = 'DURATION';
    public static $EXDATE           = 'EXDATE';
    public static $EXRULE           = 'EXRULE';
    public static $FREEBUSY         = 'FREEBUSY';
    public static $GEO              = 'GEO';
    public static $GEOLOCATION      = 'GEOLOCATION';
    public static $LAST_MODIFIED    = 'LAST-MODIFIED';
    public static $LOCATION         = 'LOCATION';
    public static $METHOD           = 'METHOD';
    public static $ORGANIZER        = 'ORGANIZER';
    public static $PERCENT_COMPLETE = 'PERCENT-COMPLETE';
    public static $PRIORITY         = 'PRIORITY';
    public static $PRODID           = 'PRODID';
    public static $RECURRENCE_ID    = 'RECURRENCE-ID';
    public static $RELATED_TO       = 'RELATED-TO';
    public static $REPEAT           = 'REPEAT';
    public static $REQUEST_STATUS   = 'REQUEST-STATUS';
    public static $RESOURCES        = 'RESOURCES';
    public static $RDATE            = 'RDATE';
    public static $RRULE            = 'RRULE';
    public static $SEQUENCE         = 'SEQUENCE';
    public static $STATUS           = 'STATUS';
    public static $SUMMARY          = 'SUMMARY';
    public static $TRANSP           = 'TRANSP';
    public static $TRIGGER          = 'TRIGGER';
    public static $TZID             = 'TZID';
    public static $TZNAME           = 'TZNAME';
    public static $TZOFFSETFROM     = 'TZOFFSETFROM';
    public static $TZOFFSETTO       = 'TZOFFSETTO';
    public static $TZURL            = 'TZURL';
    public static $UID              = 'UID';
    public static $URL              = 'URL';
    public static $VERSION          = 'VERSION';
    public static $X_PROP           = 'X-PROP';

    /**
     * @var array  iCal component collections
     * @static
     */
    public static $VCOMPS   = [
        Vcalendar::VEVENT,
        Vcalendar::VTODO,
        Vcalendar::VJOURNAL,
        Vcalendar::VFREEBUSY
    ];
    public static $MCOMPS   = [
        Vcalendar::VEVENT,
        Vcalendar::VTODO,
        Vcalendar::VJOURNAL,
        Vcalendar::VFREEBUSY,
        Vcalendar::VALARM,
        Vcalendar::VTIMEZONE
    ];
    public static $SUBCOMPS = [
        Vcalendar::VALARM,
        Vcalendar::VTIMEZONE,
        Vcalendar::STANDARD,
        Vcalendar::DAYLIGHT
    ];
    public static $TZCOMPS  = [
        Vcalendar::VTIMEZONE,
        Vcalendar::STANDARD,
        Vcalendar::DAYLIGHT
    ];
    public static $ALLCOMPS = [
        Vcalendar::VTIMEZONE,
        Vcalendar::STANDARD,
        Vcalendar::DAYLIGHT,
        Vcalendar::VEVENT,
        Vcalendar::VTODO,
        Vcalendar::VJOURNAL,
        Vcalendar::VFREEBUSY,
        Vcalendar::VALARM
    ];

    /**
     * @var array  iCal component property collections
     * @static
     */
    public static $PROPNAMES  = [
        'ACTION', 'ATTACH', 'ATTENDEE', 'CATEGORIES',
        'CLASS', 'COMMENT', 'COMPLETED', 'CONTACT',
        'CREATED', 'DESCRIPTION', 'DTEND', 'DTSTAMP',
        'DTSTART', 'DUE', 'DURATION', 'EXDATE', 'EXRULE',
        'FREEBUSY', 'GEO', 'LAST-MODIFIED', 'LOCATION',
        'ORGANIZER', 'PERCENT-COMPLETE', 'PRIORITY',
        'RECURRENCE-ID', 'RELATED-TO', 'REPEAT',
        'REQUEST-STATUS', 'RESOURCES', 'RRULE', 'RDATE',
        'SEQUENCE', 'STATUS', 'SUMMARY', 'TRANSP',
        'TRIGGER', 'TZNAME', 'TZID', 'TZOFFSETFROM',
        'TZOFFSETTO', 'TZURL', 'UID', 'URL', 'X-',
    ];

    public static $DATEPROPS  = [
        'DTSTART', 'DTEND', 'DUE', 'CREATED', 'COMPLETED',
        'DTSTAMP', 'LAST-MODIFIED', 'RECURRENCE-ID',
    ];

    public static $OTHERPROPS = [
        'ATTENDEE', 'CATEGORIES', 'CONTACT', 'LOCATION',
        'ORGANIZER', 'PRIORITY', 'RELATED-TO', 'RESOURCES',
        'STATUS', 'SUMMARY', 'UID', 'URL',
    ];

    public static $MPROPS1    = [
        'ATTENDEE', 'CATEGORIES', 'CONTACT',
        'RELATED-TO', 'RESOURCES',
    ];

    public static $MPROPS2    = [
        'ATTACH', 'ATTENDEE', 'CATEGORIES',
        'COMMENT', 'CONTACT', 'DESCRIPTION',
        'EXDATE', 'EXRULE', 'FREEBUSY', 'RDATE',
        'RELATED-TO', 'RESOURCES', 'RRULE',
        'REQUEST-STATUS', 'TZNAME', 'X-PROP',
    ];

    /**
     * @var string  iCalcreator config keys
     * @static
     */
    public static $ALLOWEMPTY       = 'ALLOWEMPTY';
    public static $COMPSINFO        = 'COMPSINFO';
    public static $DELIMITER        = 'DELIMITER';
    public static $DIRECTORY        = 'DIRECTORY';
    public static $FILENAME         = 'FILENAME';
    public static $DIRFILE          = 'DIRFILE';
    public static $FILESIZE         = 'FILESIZE';
    public static $FILEINFO         = 'FILEINFO';
    public static $LANGUAGE         = 'LANGUAGE';
    public static $PROPINFO         = 'PROPINFO';
    public static $SETPROPERTYNAMES = 'SETPROPERTYNAMES';
    public static $UNIQUE_ID        = 'UNIQUE_ID';

    /**
     * @var string  iCal date/time parameter key values
     * @static
     */
    public static $DATE                 = 'DATE';
    public static $PERIOD               = 'PERIOD';
    public static $DATE_TIME            = 'DATE-TIME';
    public static $DEFAULTVALUEDATETIME = [ 'VALUE' => 'DATE-TIME' ];
    public static $T                    = 'T';
    public static $Z                    = 'Z';
    public static $UTC                  = 'UTC';
    public static $GMT                  = 'GMT';
    public static $LCYEAR               = 'year';
    public static $LCMONTH              = 'month';
    public static $LCDAY                = 'day';
    public static $LCHOUR               = 'hour';
    public static $LCMIN                = 'min';
    public static $LCSEC                = 'sec';
    public static $LCtz                 = 'tz';
    public static $LCWEEK               = 'week';
    public static $LCTIMESTAMP          = 'timestamp';

    /**
     * @var string  iCal ATTENDEE, ORGANIZER etc param keywords
     * @static
     */
    public static $CUTYPE          = 'CUTYPE';
    public static $MEMBER          = 'MEMBER';
    public static $ROLE            = 'ROLE';
    public static $PARTSTAT        = 'PARTSTAT';
    public static $RSVP            = 'RSVP';
    public static $DELEGATED_TO    = 'DELEGATED-TO';
    public static $DELEGATED_FROM  = 'DELEGATED-FROM';
    public static $SENT_BY         = 'SENT-BY';
    public static $CN              = 'CN';
    public static $DIR             = 'DIR';
    public static $INDIVIDUAL      = 'INDIVIDUAL';
    public static $NEEDS_ACTION    = 'NEEDS-ACTION';
    public static $REQ_PARTICIPANT = 'REQ-PARTICIPANT';
    public static $false           = 'false';

    /**
     * @var array  iCal ATTENDEE, ORGANIZER etc param collections
     * @static
     */
    public static $ATTENDEEPARKEYS    = [ 'DELEGATED-FROM', 'DELEGATED-TO', 'MEMBER' ];
    public static $ATTENDEEPARALLKEYS = [
        'CUTYPE', 'MEMBER', 'ROLE', 'PARTSTAT',
        'RSVP', 'DELEGATED-TO', 'DELEGATED-FROM',
        'SENT-BY', 'CN', 'DIR', 'LANGUAGE',
    ];

    /**
     * @var string  iCal RRULE, EXRULE etc param keywords
     * @static
     */
    public static $FREQ       = 'FREQ';
    public static $UNTIL      = 'UNTIL';
    public static $COUNT      = 'COUNT';
    public static $INTERVAL   = 'INTERVAL';
    public static $WKST       = 'WKST';
    public static $BYMONTHDAY = 'BYMONTHDAY';
    public static $BYYEARDAY  = 'BYYEARDAY';
    public static $BYWEEKNO   = 'BYWEEKNO';
    public static $BYMONTH    = 'BYMONTH';
    public static $BYSETPOS   = 'BYSETPOS';
    public static $BYDAY      = 'BYDAY';
    public static $DAY        = 'DAY';

    /**
     * @var string  misc. values
     * @static
     */
    public static $X_            = 'X-';
    public static $ALTREP        = 'ALTREP';
    public static $ALTRPLANGARR  = [ 'ALTREP', 'LANGUAGE' ];
    public static $VALUE         = 'VALUE';
    public static $BINARY        = 'BINARY';
    public static $LCvalue       = 'value';
    public static $LCparams      = 'params';
    public static $UNPARSEDTEXT  = 'unparsedtext';
    public static $SERVER_NAME   = 'SERVER_NAME';
    public static $LOCALHOST     = 'localhost';
    public static $FMTBEGIN      = "BEGIN:%s\r\n";
    public static $FMTEND        = "END:%s\r\n";
    public static $CRLF          = "\r\n";
    public static $COMMA         = ',';
    public static $COLON         = ':';
    public static $QQ            = '"';
    public static $SEMIC         = ';';
    public static $MINUS         = '-';
    public static $PLUS          = '+';
    public static $PLUSMINUSARR  = [ '+', '-' ];
    public static $SP0           = '';
    public static $SP1           = ' ';
    public static $ZERO          = '0';
    public static $DOT           = '.';
    public static $L             = '/';

    /**
     * @var string  Util date/datetime formats
     * @static
     */
    public static $YMDHIS3 = 'Y-m-d-H-i-s';

    /**
     * Initiates configuration, set defaults
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-03-11
     * @param array $config
     * @return array
     * @static
     */
    public static function initConfig( $config ) {
        $config = array_change_key_case( $config, CASE_UPPER );
        if( ! isset( $config[Util::$ALLOWEMPTY] )) {
            $config[Util::$ALLOWEMPTY] = true;
        }
        if( ! isset( $config[Util::$DELIMITER] )) {
            $config[Util::$DELIMITER] = DIRECTORY_SEPARATOR;
        }
        if( ! isset( $config[Util::$DIRECTORY] )) {
            $config[Util::$DIRECTORY] = Util::$DOT;
        }
        return $config;
    }

    /**
     * Return bool true if comptype is in array
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26 - 2018-11-03
     * @param string $compType   component name
     * @param array  $compList   list of components
     * @return bool
     * @static
     */
    public static function isCompInList( $compType, array $compList ) {
        return in_array( ucfirst( strtolower( $compType )), $compList);
    }

    /**
     * Return bool true if property is in array
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26 - 2018-11-04
     * @param string $propName   property name
     * @param array  $propList   list of properties
     * @return bool
     * @static
     */
    public static function isPropInList( $propName, array $propList ) {
        return in_array( strtoupper( $propName ), $propList);
    }

    /**
     * Return date YMD string
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26 - 2018-11-05
     * @param array  $date
     * @return string
     * @static
     */
    public static function getYMDString( array $date ) {
        static $YMD = '%04d%02d%02d';
        return sprintf( $YMD, (int) $date[Util::$LCYEAR], (int) $date[Util::$LCMONTH], (int) $date[Util::$LCDAY] );
    }

    /**
     * Return date His string
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26 - 2018-11-05
     * @param array  $date
     * @return string
     * @static
     */
    public static function getHisString( array $date ) {
        static $HIS = '%02d%02d%02d';
        return sprintf( $HIS, (int) $date[Util::$LCHOUR], (int) $date[Util::$LCMIN], (int) $date[Util::$LCSEC] );
    }

    /**
     * Return date YMDHISE string
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.7 - 2018-11-27
     * @param array  $date
     * @param string $tz
     * @return string
     * @static
     */
    public static function getYMDHISEString( array $date, $tz=null ) {
        static $YMDHISE = '%04d-%02d-%02d %02d:%02d:%02d %s';
        if( ! isset( $date[Util::$LCvalue] )) {
            $date = [ Util::$LCvalue => $date ];
        }
        return trim(
            sprintf(
                $YMDHISE,
                (int) $date[Util::$LCvalue][Util::$LCYEAR],
                (int) $date[Util::$LCvalue][Util::$LCMONTH],
                (int) $date[Util::$LCvalue][Util::$LCDAY],
                (int) $date[Util::$LCvalue][Util::$LCHOUR],
                (int) $date[Util::$LCvalue][Util::$LCMIN],
                (int) $date[Util::$LCvalue][Util::$LCSEC],
                $tz
            )
        );
    }

    /**
     * Ensure array datetime
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26 - 2018-11-05
     * @param array  $date
     * @param string $tz
     * @param int    $parno
     * @return array
     * @static
     */
    public static function ensureArrDatetime( array $date, $tz, $parno ) {
        return Util::strDate2ArrayDate( Util::getYMDHISEString( $date, $tz ), $parno );
    }

    /**
     * Return formatted output for calendar component property
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.20 - 2017-01-30
     * @param string $label      property name
     * @param string $attributes property attributes
     * @param string $content    property content
     * @return string
     * @static
     */
    public static function createElement( $label, $attributes = null, $content = null ) {
        $output = strtoupper( $label );
        if( ! empty( $attributes )) {
            $output .= trim( $attributes );
        }
        $output .= Util::$COLON . trim( $content );
        return Util::size75( $output );
    }

    /**
     * Return formatted output for calendar component property parameters
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.1 - 2018-12-01
     * @param array  $params
     * @param array  $ctrKeys
     * @param string $lang
     * @return string
     * @static
     */
    public static function createParams( $params = null, $ctrKeys = null, $lang = null ) {
        static $FMTFMTTYPE  = ';FMTTYPE=%s%s';
        static $FMTKEQV     = '%s=%s';
        static $ENCODING    = 'ENCODING';
        static $FMTTYPE     = 'FMTTYPE';
        static $RANGE       = 'RANGE';
        static $RELTYPE     = 'RELTYPE';
        static $PARAMSARRAY = null;
        if( is_null( $PARAMSARRAY )) {
            $PARAMSARRAY = [
                Util::$ALTREP,
                Util::$CN,
                Util::$DIR,
                $ENCODING,
                $FMTTYPE,
                Util::$LANGUAGE,
                $RANGE,
                $RELTYPE,
                Util::$SENT_BY,
                Util::$TZID,
                Util::$VALUE,
            ];
        }
        static $FMTQ   = '"%s"';
        static $FMTQTD = ';%s=%s%s%s';
        static $FMTCMN = ';%s=%s';
        if( empty( $params ) && empty( $ctrKeys ) && empty( $lang )) {
            return Util::$SP0;
        }
        if( ! is_array( $params )) {
            $params = [];
        }
        if( ! is_array( $ctrKeys ) || empty( $ctrKeys )) {
            $ctrKeys = [];
        }
        $attrLANG       = $attr1 = $attr2 = null;
        $hasCNattrKey   = ( in_array( Util::$CN, $ctrKeys ));
        $hasLANGattrKey = ( in_array( Util::$LANGUAGE, $ctrKeys ));
        $CNattrExist    = false;
        $xparams        = [];
        $params         = array_change_key_case( $params, CASE_UPPER );
        foreach( $params as $paramKey => $paramValue ) {
            if(( false !== strpos( $paramValue, Util::$COLON )) ||
               ( false !== strpos( $paramValue, Util::$SEMIC )) ||
               ( false !== strpos( $paramValue, Util::$COMMA ))) {
                $paramValue = sprintf( $FMTQ, $paramValue );
            }
            if( ctype_digit((string) $paramKey )) {
                $xparams[] = $paramValue;
                continue;
            }
            if( ! in_array( $paramKey, $PARAMSARRAY )) {
                $xparams[$paramKey] = $paramValue;
            }
            else {
                $params[$paramKey] = $paramValue;
            }
        }
        ksort( $xparams, SORT_STRING );
        foreach( $xparams as $paramKey => $paramValue ) {
            $attr2 .= Util::$SEMIC;
            $attr2 .= ( ctype_digit((string) $paramKey ))
                ? $paramValue
                : sprintf( $FMTKEQV, $paramKey, $paramValue );
        }
        if( isset( $params[$FMTTYPE] ) && ! in_array( $FMTTYPE, $ctrKeys )) {
            $attr1 .= sprintf( $FMTFMTTYPE, $params[$FMTTYPE], $attr2 );
            $attr2 = null;
        }
        if( isset( $params[$ENCODING] ) && ! in_array( $ENCODING, $ctrKeys )) {
            if( ! empty( $attr2 )) {
                $attr1 .= $attr2;
                $attr2 = null;
            }
            $attr1 .= sprintf( $FMTCMN, $ENCODING, $params[$ENCODING] );
        }
        if( isset( $params[Util::$VALUE] ) && ! in_array( Util::$VALUE, $ctrKeys )) {
            $attr1 .= sprintf( $FMTCMN, Util::$VALUE, $params[Util::$VALUE] );
        }
        if( isset( $params[Util::$TZID] ) && ! in_array( Util::$TZID, $ctrKeys )) {
            $attr1 .= sprintf( $FMTCMN, Util::$TZID, $params[Util::$TZID] );
        }
        if( isset( $params[$RANGE] ) && ! in_array( $RANGE, $ctrKeys )) {
            $attr1 .= sprintf( $FMTCMN, $RANGE, $params[$RANGE] );
        }
        if( isset( $params[$RELTYPE] ) && ! in_array( $RELTYPE, $ctrKeys )) {
            $attr1 .= sprintf( $FMTCMN, $RELTYPE, $params[$RELTYPE] );
        }
        if( isset( $params[Util::$CN] ) && $hasCNattrKey ) {
            $attr1       = sprintf( $FMTCMN, Util::$CN, $params[Util::$CN] );
            $CNattrExist = true;
        }
        if( isset( $params[Util::$DIR] ) && in_array( Util::$DIR, $ctrKeys )) {
            $delim = ( false !== strpos( $params[Util::$DIR], Util::$QQ )) ? null : Util::$QQ;
            $attr1 .= sprintf( $FMTQTD, Util::$DIR, $delim, $params[Util::$DIR], $delim );
        }
        if( isset( $params[Util::$SENT_BY] ) && in_array( Util::$SENT_BY, $ctrKeys )) {
            $attr1 .= sprintf( $FMTCMN, Util::$SENT_BY, $params[Util::$SENT_BY] );
        }
        if( isset( $params[Util::$ALTREP] ) && in_array( Util::$ALTREP, $ctrKeys )) {
            $delim = ( false !== strpos( $params[Util::$ALTREP], Util::$QQ )) ? null : Util::$QQ;
            $attr1 .= sprintf( $FMTQTD, Util::$ALTREP, $delim, $params[Util::$ALTREP], $delim );
        }
        if( isset( $params[Util::$LANGUAGE] ) && $hasLANGattrKey ) {
            $attrLANG .= sprintf( $FMTCMN, Util::$LANGUAGE, $params[Util::$LANGUAGE] );
        }
        elseif(( $CNattrExist || $hasLANGattrKey ) && ! empty( $lang )) {
            $attrLANG .= sprintf( $FMTCMN, Util::$LANGUAGE, $lang );
        }
        return $attr1 . $attrLANG . $attr2;
    }

    /**
     * Return (conformed) iCal component property parameters
     *
     * Trim quoted values, default parameters may be set, if missing
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-04-08
     * @param array $params
     * @param array $defaults
     * @return array
     * @static
     */
    public static function setParams( $params, $defaults = null ) {
        if( ! is_array( $params )) {
            $params = [];
        }
        $output = [];
        $params = array_change_key_case( $params, CASE_UPPER );
        foreach( $params as $paramKey => $paramValue ) {
            if( is_array( $paramValue )) {
                foreach( $paramValue as $pkey => $pValue ) {
                    $paramValue[$pkey] = trim( $pValue, Util::$QQ );
                }
            }
            else {
                $paramValue = trim( $paramValue, Util::$QQ );
            }
            if( Util::$VALUE == $paramKey ) {
                $output[Util::$VALUE] = strtoupper( $paramValue );
            }
            else {
                $output[$paramKey] = $paramValue;
            }
        } // end foreach
        if( is_array( $defaults )) {
            $output = array_merge( array_change_key_case( $defaults, CASE_UPPER ), $output );
        }
        return ( 0 < count( $output )) ? $output : null;
    }

    /**
     * Remove expected key/value from array and returns foundValue (if found) else returns elseValue
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.24.1 - 2018-10-22
     * @param null|array $array          iCal property parameters
     * @param string     $expectedKey    expected key
     * @param string     $expectedValue  expected value
     * @param int        $returnValue    return value if found
     * @param int        $elseValue      return value if not found
     * @param int        $preSet         return value if already preset
     * @return int
     * @static
     */
    public static function existRem(
        & $array,
          $expectedKey,
          $expectedValue  = null,
          $returnValue    = null,
          $elseValue      = null,
          $preSet         = null
    ) {
        if( $preSet ) {
            return $preSet;
        }
        if( empty( $array )) {
            return $elseValue;
        }
        foreach( $array as $key => $value ) {
            if( 0 == strcasecmp( $expectedKey, $key )) {
                if( empty( $expectedValue ) || ( 0 == strcasecmp( $expectedValue, $value ))) {
                    unset( $array[$key] );
                    return $returnValue;
                }
            }
        }
        return $elseValue;
    }

    /**
     * Delete component property value, managing components with multiple occurencies
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.8.8 - 2011-03-15
     * @param array $multiprop component (multi-)property
     * @param int   $propix    removal counter
     * @return bool true
     * @static
     */
    public static function deletePropertyM( & $multiprop, & $propix ) {
        if( isset( $multiprop[$propix] )) {
            unset( $multiprop[$propix] );
        }
        if( empty( $multiprop )) {
            $multiprop = null;
            unset( $propix );
            return false;
        }
        return true;
    }

    /**
     * Recount property propix, used at consecutive getProperty calls
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.23.8 - 2017-04-18
     * @param array $prop   component (multi-)property
     * @param int   $propix getter counter
     * @return bool true
     * @static
     */
    public static function recountMvalPropix( & $prop, & $propix ) {
        if( ! is_array( $prop ) || empty( $prop )) {
            return false;
        }
        $last = key( array_slice( $prop, -1, 1, true ));
        while( ! isset( $prop[$propix] ) && ( $last > $propix )) {
            $propix++;
        }
        return true;
    }

    /**
     * Check index and set (an indexed) content in a multiple value array
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-04-08
     * @param array $valArr
     * @param mixed $value
     * @param array $params
     * @param array $defaults
     * @param int   $index
     * @static
     */
    public static function setMval(
        & $valArr,
          $value,
          $params   = null,
          $defaults = null,
          $index    = null
    ) {
        if( ! is_array( $valArr )) {
            $valArr = [];
        }
        if( ! is_null( $params )) {
            $params = Util::setParams( $params, $defaults );
        }
        if( is_null( $index )) { // i.e. next
            $valArr[] = [
                Util::$LCvalue  => $value,
                Util::$LCparams => $params,
            ];
            return;
        }
        $index = $index - 1;
        if( isset( $valArr[$index] )) { // replace
            $valArr[$index] = [
                Util::$LCvalue  => $value,
                Util::$LCparams => $params,
            ];
            return;
        }
        $valArr[$index] = [
            Util::$LCvalue  => $value,
            Util::$LCparams => $params,
        ];
        ksort( $valArr ); // order
    }

    /**
     * Return datestamp for calendar component object instance dtstamp
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-02-17
     * @return array
     * @static
     */
    public static function makeDtstamp() {
        $date = explode( Util::$MINUS, gmdate( Util::$YMDHIS3, time()));
        return [
            Util::$LCvalue  => [
                Util::$LCYEAR  => $date[0],
                Util::$LCMONTH => $date[1],
                Util::$LCDAY   => $date[2],
                Util::$LCHOUR  => $date[3],
                Util::$LCMIN   => $date[4],
                Util::$LCSEC   => $date[5],
                Util::$LCtz    => Util::$Z,
            ],
            Util::$LCparams => null,
        ];
    }

    /**
     * Return an unique id for a calendar component object instance
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-02-17
     * @param string $unique_id
     * @return array
     * @static
     */
    public static function makeUid( $unique_id ) {
        static $FMT = '%s-%s@%s';
        static $TMDTHIS = 'Ymd\THisT';
        return [
            Util::$LCvalue  => sprintf(
                $FMT,
                date( $TMDTHIS ),
                substr( microtime(), 2, 4 ) . Util::getRandChars( 6 ),
                $unique_id
            ),
            Util::$LCparams => null,
        ];
    }

    /**
     * Return a random (and unique) sequence of characters
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-02-18
     * @param int $cnt
     * @return string
     * @access private
     * @static
     */
    private static function getRandChars( $cnt ) {
        $cnt = (int) floor( $cnt / 2 );
        $x   = 0;
        do {
            $randChars = bin2hex( openssl_random_pseudo_bytes( $cnt, $cStrong ));
            $x         += 1;
        } while(( 3 > $x ) && ( false == $cStrong ));
        return $randChars;
    }

    /**
     * Return true if a date property has NO date parts
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-02-17
     * @param array $content
     * @return bool
     * @static
     */
    public static function hasNodate( $content ) {
        return (
            ! isset( $content[Util::$LCvalue][Util::$LCYEAR] ) &&
            ! isset( $content[Util::$LCvalue][Util::$LCMONTH] ) &&
            ! isset( $content[Util::$LCvalue][Util::$LCDAY] ) &&
            ! isset( $content[Util::$LCvalue][Util::$LCHOUR] ) &&
            ! isset( $content[Util::$LCvalue][Util::$LCMIN] ) &&
            ! isset( $content[Util::$LCvalue][Util::$LCSEC] ));
    }

    /**
     * Return true if property parameter VALUE is set to argument, otherwise false
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-02-12
     * @param array  $content
     * @param string $arg
     * @return bool
     * @static
     */
    public static function isParamsValueSet( array $content, $arg ) {
        return ( isset( $content[Util::$LCparams][Util::$VALUE] ) &&
              ( $arg == $content[Util::$LCparams][Util::$VALUE] ));
    }

    /**
     * Return bool true if name is X-prefixed
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-02-17
     * @param string $name
     * @return bool
     * @static
     */
    public static function isXprefixed( $name ) {
        return ( 0 == strcasecmp( self::$X_, substr( $name, 0, 2 )));
    }

    /**
     * Return property name  and  opt.params and property value
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.23.8 - 2017-04-16
     * @param  string $row
     * @return array
     * @static
     */
    public static function getPropName( $row ) {
        static $COLONSEMICARR = [ ':', ';' ];
        $propName = null;
        $cix      = 0;
        $len      = strlen( $row );
        while( $cix < $len ) {
            if( in_array( $row[$cix], $COLONSEMICARR )) {
                break;
            }
            $propName .= $row[$cix];
            $cix++;
        } // end while...
        if( isset( $row[$cix] )) {
            $row = substr( $row, $cix );
        }
        else {
            $propName = Util::trimTrailNL( $propName ); // property without colon and content
            $row      = null;
        }
        return [ $propName, $row ];
    }

    /**
     * Return array from content split by '\,'
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.23.8 - 2017-04-16
     * @param string $content
     * @return array
     * @static
     */
    public static function commaSplit( $content ) {
        static $DBBS = "\\";
        $output = [ 0 => null ];
        $cix    = $lix = 0;
        $len    = strlen( $content );
        while( $lix < $len ) {
            if(( Util::$COMMA == $content[$lix] ) && ( $DBBS != $content[( $lix - 1 )] )) {
                $output[++$cix] = null;
            }
            else {
                $output[$cix] .= $content[$lix];
            }
            $lix++;
        }
        return array_filter( $output );
    }

    /**
     * Return concatenated calendar rows, one row for each property
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-02-17
     * @param array $rows
     * @return array
     * @static
     */
    public static function concatRows( $rows ) {
        $output = [];
        $cnt    = count( $rows );
        for( $i = 0; $i < $cnt; $i++ ) {
            $line = rtrim( $rows[$i], Util::$CRLF );
            while( isset( $rows[$i + 1] ) &&
                 ! empty( $rows[$i + 1] ) &&
                 ( Util::$SP1 == $rows[$i + 1]{0} )) {
                $line .= rtrim( substr( $rows[++$i], 1 ), Util::$CRLF );
            }
            $output[] = $line;
        }
        return $output;
    }

    /**
     * Return string with removed ical line folding
     *
     * Remove any line-endings that may include spaces or tabs
     * and convert all line endings (iCal default '\r\n'),
     * takes care of '\r\n', '\r' and '\n' and mixed '\r\n'+'\r', '\r\n'+'\n'
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-03-01
     * @param string $text
     * @return array
     * @static
     */
    public static function convEolChar( & $text ) {
        static $BASEDELIM  = null;
        static $BASEDELIMs = null;
        static $EMPTYROW   = null;
        static $FMT        = '%1$s%2$75s%1$s';
        static $CRLFs      = [ "\r\n", "\n\r", "\n", "\r" ];
        static $CRLFexts   = [ "\r\n ", "\n\r\t" ];
        /* fix dummy line separator etc */
        if( empty( $BASEDELIM )) {
            $BASEDELIM  = Util::getRandChars( 16 );
            $BASEDELIMs = $BASEDELIM . $BASEDELIM;
            $EMPTYROW   = sprintf( $FMT, $BASEDELIM, Util::$SP0 );
        }
        /* fix eol chars */
        $text = str_replace( $CRLFs, $BASEDELIM, $text );
        /* fix empty lines */
        $text = str_replace( $BASEDELIMs, $EMPTYROW, $text );
        /* fix line folding */
        $text = str_replace( $BASEDELIM, Util::$CRLF, $text );
        $text = str_replace( $CRLFexts, null, $text );
        /* split in component/property lines */
        return explode( Util::$CRLF, $text );
    }

    /**
     * Return wrapped string with (byte oriented) line breaks at pos 75
     *
     * Lines of text SHOULD NOT be longer than 75 octets, excluding the line
     * break. Long content lines SHOULD be split into a multiple line
     * representations using a line "folding" technique. That is, a long
     * line can be split between any two characters by inserting a CRLF
     * immediately followed by a single linear white space character (i.e.,
     * SPACE, US-ASCII decimal 32 or HTAB, US-ASCII decimal 9). Any sequence
     * of CRLF followed immediately by a single linear white space character
     * is ignored (i.e., removed) when processing the content type.
     *
     * Edited 2007-08-26 by Anders Litzell, anders@litzell.se to fix bug where
     * the reserved expression "\n" in the arg $string could be broken up by the
     * folding of lines, causing ambiguity in the return string.
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-03-01
     * @param string $string
     * @return string
     * @access private
     * @static
     * @link   http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
     */
    private static function size75( $string ) {
        static $DBS = '\\';
        static $LCN = 'n';
        static $UCN = 'N';
        static $SPBSLCN = ' \n';
        static $SP1 = ' ';
        $tmp    = $string;
        $string = null;
        $cCnt   = $x = 0;
        while( true ) {
            if( ! isset( $tmp[$x] )) {
                $string .= Util::$CRLF;        // loop breakes here
                break;
            }
            elseif(( 74 <= $cCnt ) &&
                ( $DBS == $tmp[$x] ) &&
                (( $LCN == $tmp[$x + 1] ) || ( $UCN == $tmp[$x + 1] ))) {
                $string .= Util::$CRLF . $SPBSLCN; // don't break lines inside '\n'
                $x      += 2;
                if( ! isset( $tmp[$x] )) {
                    $string .= Util::$CRLF;
                    break;
                }
                $cCnt = 3;
            }
            elseif( 75 <= $cCnt ) {
                $string .= Util::$CRLF . $SP1;
                $cCnt   = 1;
            }
            $byte   = ord( $tmp[$x] );
            $string .= $tmp[$x];
            switch( true ) {
                case(( $byte >= 0x20 ) && ( $byte <= 0x7F )) :
                    $cCnt += 1;                    // characters U-00000000 - U-0000007F (same as ASCII)
                    break;                         // add a one byte character
                case(( $byte & 0xE0 ) == 0xC0 ) :  // characters U-00000080 - U-000007FF, mask 110XXXXX
                    if( isset( $tmp[$x + 1] )) {
                        $cCnt   += 1;
                        $string .= $tmp[$x + 1];
                        $x      += 1;              // add a two bytes character
                    }
                    break;
                case(( $byte & 0xF0 ) == 0xE0 ) :  // characters U-00000800 - U-0000FFFF, mask 1110XXXX
                    if( isset( $tmp[$x + 2] )) {
                        $cCnt   += 1;
                        $string .= $tmp[$x + 1] . $tmp[$x + 2];
                        $x      += 2;              // add a three bytes character
                    }
                    break;
                case(( $byte & 0xF8 ) == 0xF0 ) :  // characters U-00010000 - U-001FFFFF, mask 11110XXX
                    if( isset( $tmp[$x + 3] )) {
                        $cCnt   += 1;
                        $string .= $tmp[$x + 1] . $tmp[$x + 2] . $tmp[$x + 3];
                        $x      += 3;              // add a four bytes character
                    }
                    break;
                case(( $byte & 0xFC ) == 0xF8 ) :  // characters U-00200000 - U-03FFFFFF, mask 111110XX
                    if( isset( $tmp[$x + 4] )) {
                        $cCnt   += 1;
                        $string .= $tmp[$x + 1] . $tmp[$x + 2] . $tmp[$x + 3] . $tmp[$x + 4];
                        $x      += 4;              // add a five bytes character
                    }
                    break;
                case(( $byte & 0xFE ) == 0xFC ) :  // characters U-04000000 - U-7FFFFFFF, mask 1111110X
                    if( isset( $tmp[$x + 5] )) {
                        $cCnt   += 1;
                        $string .= $tmp[$x + 1] . $tmp[$x + 2] . $tmp[$x + 3] . $tmp[$x + 4] . $tmp[$x + 5];
                        $x      += 5;              // add a six bytes character
                    }
                    break;
                default:                           // add any other byte without counting up $cCnt
                    break;
            } // end switch( true )
            $x += 1;                 // next 'byte' to test
        } // end while( true )
        return $string;
    }

    /**
     * Separate (string) to iCal property value and attributes
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.23.13 - 2017-05-02
     * @param string $line     property content
     * @param array  $propAttr property parameters
     * @static
     * @TODO   same as in Util::calAddressCheck() ??
     */
    public static function splitContent( & $line, & $propAttr = null ) {
        static $CSS = '://';
        static $MSTZ = [ 'utc-', 'utc+', 'gmt-', 'gmt+' ];
        static $PROTO3 = [ 'fax:', 'cid:', 'sms:', 'tel:', 'urn:' ];
        static $PROTO4 = [ 'crid:', 'news:', 'pres:' ];
        static $PROTO6 = [ 'mailto:' ];
        static $EQ = '=';
        $attr         = [];
        $attrix       = -1;
        $clen         = strlen( $line );
        $WithinQuotes = false;
        $len          = strlen( $line );
        $cix          = 0;
        while( $cix < $len ) {
            if( ! $WithinQuotes && ( Util::$COLON == $line[$cix] ) &&
                ( substr( $line, $cix, 3 ) != $CSS ) &&
                ( ! in_array( strtolower( substr( $line, $cix - 6, 4 )), $MSTZ )) &&
                ( ! in_array( strtolower( substr( $line, $cix - 3, 4 )), $PROTO3 )) &&
                ( ! in_array( strtolower( substr( $line, $cix - 4, 5 )), $PROTO4 )) &&
                ( ! in_array( strtolower( substr( $line, $cix - 6, 7 )), $PROTO6 ))) {
                $attrEnd = true;
                if(( $cix < ( $clen - 4 )) &&
                    ctype_digit( substr( $line, $cix + 1, 4 ))) { // an URI with a (4pos) portnr??
                    for( $c2ix = $cix; 3 < $c2ix; $c2ix-- ) {
                        if( $CSS == substr( $line, $c2ix - 2, 3 )) {
                            $attrEnd = false;
                            break; // an URI with a portnr!!
                        }
                    }
                }
                if( $attrEnd ) {
                    $line = substr( $line, ( $cix + 1 ));
                    break;
                }
                $cix++;
            } // end if(  ! $WithinQuotes...
            if( Util::$QQ == $line[$cix] ) { // '"'
                $WithinQuotes = ! $WithinQuotes;
            }
            if( Util::$SEMIC == $line[$cix] ) { // ';'
                $attr[++$attrix] = null;
            }
            else {
                if( 0 > $attrix ) {
                    $attrix = 0;
                }
                $attr[$attrix] .= $line[$cix];
            }
            $cix++;
        } // end while...
        /* make attributes in array format */
        $propAttr = [];
        foreach( $attr as $attribute ) {
            $attrsplit = explode( $EQ, $attribute, 2 );
            if( 1 < count( $attrsplit )) {
                $propAttr[$attrsplit[0]] = $attrsplit[1];
            }
        }
    }

    /**
     * Special characters management output
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.23.8 - 2017-04-17
     * @param string $string
     * @return string
     * @static
     */
    public static function strrep( $string ) {
        static $BSLCN    = '\n';
        static $SPECCHAR = [ 'n', 'N', 'r', ',', ';' ];
        static $DBS      = "\\";
        static $SQ       = "'";
        static $BSCOMMA  = '\,';
        static $BSSEMIC  = '\;';
        static $BSLCR    = "\r";
        static $QBSLCN   = "\n";
        static $BSUCN    = '\N';
        $string = (string) $string;
        $strLen = strlen( $string );
        $pos    = 0;
        while( $pos < $strLen ) {
            if( false === ( $pos = strpos( $string, $DBS, $pos ))) {
                break;
            }
            if( ! in_array( substr( $string, $pos, 1 ), $SPECCHAR )) {
                $string = substr( $string, 0, $pos ) . $DBS . substr( $string, ( $pos + 1 ));
                $pos    += 1;
            }
            $pos += 1;
        }
        if( false !== strpos( $string, Util::$QQ )) {
            $string = str_replace( Util::$QQ, $SQ, $string );
        }
        if( false !== strpos( $string, Util::$COMMA )) {
            $string = str_replace( Util::$COMMA, $BSCOMMA, $string );
        }
        if( false !== strpos( $string, Util::$SEMIC )) {
            $string = str_replace( Util::$SEMIC, $BSSEMIC, $string );
        }
        if( false !== strpos( $string, Util::$CRLF )) {
            $string = str_replace( Util::$CRLF, $BSLCN, $string );
        }
        elseif( false !== strpos( $string, $BSLCR )) {
            $string = str_replace( $BSLCR, $BSLCN, $string );
        }
        elseif( false !== strpos( $string, $QBSLCN )) {
            $string = str_replace( $QBSLCN, $BSLCN, $string );
        }
        if( false !== strpos( $string, $BSUCN )) {
            $string = str_replace( $BSUCN, $BSLCN, $string );
        }
        $string = str_replace( Util::$CRLF, $BSLCN, $string );
        return $string;
    }

    /**
     * Special characters management input
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.2 - 2015-06-25
     * @param string $string
     * @return string
     * @static
     */
    public static function strunrep( $string ) {
        static $BS4 = '\\\\';
        static $BS2 = '\\';
        static $BSCOMMA = '\,';
        static $BSSEMIC = '\;';
        $string = str_replace( $BS4, $BS2, $string );
        $string = str_replace( $BSCOMMA, Util::$COMMA, $string );
        $string = str_replace( $BSSEMIC, Util::$SEMIC, $string );
        return $string;
    }

    /**
     * Return string with trimmed trailing \n
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-02-17
     * @param string $value
     * @return string
     * @static
     */
    public static function trimTrailNL( $value ) {
        static $NL = '\n';
        if( $NL == strtolower( substr( $value, -2 ))) {
            $value = substr( $value, 0, ( strlen( $value ) - 2 ));
        }
        return $value;
    }

    /**
     * Return internal date (format) with parameters based on input date
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.7 - 2018-11-24
     * @param mixed  $year
     * @param mixed  $month
     * @param int    $day
     * @param int    $hour
     * @param int    $min
     * @param int    $sec
     * @param string $tz
     * @param array  $params
     * @param string $caller
     * @param string $compType
     * @param string $tzId
     * @return array
     * @static
     */
    public static function setDate(
        $year,
        $month    = null,
        $day      = null,
        $hour     = null,
        $min      = null,
        $sec      = null,
        $tz       = null,
        $params   = null,
        $caller   = null,
        $compType = null,
        $tzId     = null
    ) {
        $input     = [];
        $parno     = null;
        $localtime = (( Util::$DTSTART == $caller ) &&
            Util::isCompInList( $compType, Util::$TZCOMPS )) ? true : false;
        Util::strDate2arr( $year );
        switch( true ) {
            case ( $year instanceof DateTime ) :
                $input = self::dateTime2Arr( $year, $month, $localtime, $parno );
                break;
            case ( Util::isArrayDate( $year )) :
                $parno = self::setDateIsArrayDate( $input, $year, $month, $tzId, $localtime );
                break;
            case ( Util::isArrayTimestampDate( $year )) :
                $parno = self::setDateIsArrayTimestampDate( $input, $year, $month, $tzId, $localtime );
                break;
            case ( is_string( $year ) && ( 8 <= strlen( trim((string) $year )))) :
                // string ex. "2006-08-03 10:12:18 [[[+/-]1234[56]] / timezone]"
                $parno = self::setDateIsStringDate( $input, $year, $month, $tzId, $localtime );
                break;
            default : // using all (?) args
                $parno = self::setDateIsAllArgsDate($input, $year, $month, $day, $hour, $min, $sec,
                                                    $tz, $params, $tzId, $localtime );
                break;
        }
        self::setDateCheckValueAndTimezone( $input, $parno );
        if( $localtime ) {
            unset( $input[Util::$LCvalue][Util::$LCtz], $input[Util::$LCparams][Util::$TZID] );
        }
        return $input;
    }

    /**
     * Ensure internal date (format) with parameters based on input array date
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.6 - 2015-11-19
     * @param array  $rDate
     * @param mixed  $arrDate
     * @param mixed  $params
     * @param string $tzId
     * @param bool   $localtime
     * @return int
     * @access private
     * @static
     */
    private static function setDateIsArrayDate( array & $rDate, $arrDate, $params, $tzId, $localtime ) {
        $rDate[Util::$LCvalue] = Util::chkDateArr( $arrDate );
        if( 100 > $rDate[Util::$LCvalue][Util::$LCYEAR] ) {
            $rDate[Util::$LCvalue][Util::$LCYEAR] += 2000;
        }
        if( $localtime ) {
            unset( $params[Util::$VALUE], $params[Util::$TZID] );
        }
        elseif( ! isset( $params[Util::$TZID] ) && isset( $tzId ) ) {
            $params[Util::$TZID] = $tzId;
        }
        if( isset( $rDate[Util::$LCvalue][Util::$LCtz] ) &&
            Util::isOffset( $rDate[Util::$LCvalue][Util::$LCtz] ) ) {
            unset( $params[Util::$TZID] );
        }
        elseif( ! isset( $rDate[Util::$LCvalue][Util::$LCtz] ) &&
            isset( $params[Util::$TZID] ) &&
            Util::isOffset( $params[Util::$TZID] ) ) {
            $rDate[Util::$LCvalue][Util::$LCtz] = $params[Util::$TZID];
            unset( $params[Util::$TZID] );
        }
        $rDate[Util::$LCparams] = Util::setParams( $params, Util::$DEFAULTVALUEDATETIME );
        $foundValue = ( isset( $rDate[Util::$LCvalue][Util::$LCtz] ) ) ? 7 : 6;
        $parno      = Util::existRem(
            $rDate[Util::$LCparams],
            Util::$VALUE,
            Util::$DATE_TIME,
            $foundValue
        );
        $parno      = Util::existRem(
            $rDate[Util::$LCparams],
            Util::$VALUE,
            Util::$DATE,
            3,
            count( $rDate[Util::$LCvalue] ),
            $parno
        );
        if( 6 > $parno ) {
            unset(
                $rDate[Util::$LCvalue][Util::$LCtz],
                $rDate[Util::$LCparams][Util::$TZID],
                $tzId
            );
        }
        if( ( 6 <= $parno ) &&
            isset( $rDate[Util::$LCvalue][Util::$LCtz] ) &&
            ( Util::$Z != $rDate[Util::$LCvalue][Util::$LCtz] ) &&
            Util::isOffset( $rDate[Util::$LCvalue][Util::$LCtz] ) ) {
            $rDate[Util::$LCvalue] = Util::ensureArrDatetime( $rDate, $rDate[Util::$LCvalue][Util::$LCtz], $parno );
            unset( $rDate[Util::$LCvalue][Util::$UNPARSEDTEXT],
                $rDate[Util::$LCparams][Util::$TZID]
            );
        }
        if( isset( $rDate[Util::$LCvalue][Util::$LCtz] ) &&
            ! Util::isOffset( $rDate[Util::$LCvalue][Util::$LCtz] ) ) {
            $rDate[Util::$LCparams][Util::$TZID] = $rDate[Util::$LCvalue][Util::$LCtz];
            unset( $rDate[Util::$LCvalue][Util::$LCtz] );
        }
        return $parno;
    }

    /**
     * Ensure internal date (format) with parameters based on input array timestamp date
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.6 - 2018-11-23
     * @param array  $rDate
     * @param mixed  $arrTimestamp
     * @param mixed  $params
     * @param string $tzId
     * @param bool   $localtime
     * @return int
     * @access private
     * @static
     */
    private static function setDateIsArrayTimestampDate( array & $rDate, $arrTimestamp, $params, $tzId, $localtime ) {
        if( $localtime ) {
            foreach( $params as $k => $v ) {
                if( 0 == strcasecmp( Util::$VALUE, $k )) {
                    unset( $params[$k ] );
                }
                if( 0 == strcasecmp( Util::$TZID, $k )) {
                    unset( $params[$k ] );
                }
            }
        }
        $rDate[Util::$LCparams] = Util::setParams( $params, Util::$DEFAULTVALUEDATETIME );
        $parno      = Util::existRem( $rDate[Util::$LCparams], Util::$VALUE, Util::$DATE, 3 );
        $parno      = Util::existRem(
            $rDate[Util::$LCparams],
            Util::$VALUE, Util::$DATE_TIME,
            7,
            $parno
        );
        if( isset( $arrTimestamp[Util::$LCtz] ) && ! empty( $arrTimestamp[Util::$LCtz] ) ) {
            if( ! Util::isOffset( $arrTimestamp[Util::$LCtz] ) ) {
                $rDate[Util::$LCparams][Util::$TZID] = $arrTimestamp[Util::$LCtz];
                unset( $arrTimestamp[Util::$LCtz], $tzId );
            }
            else {
                if( isset( $rDate[Util::$LCparams][Util::$TZID] ) &&
                    ! empty( $rDate[Util::$LCparams][Util::$TZID] ) ) {
                    if( ! Util::isOffset( $rDate[Util::$LCparams][Util::$TZID] ) ) {
                        unset( $tzId );
                    }
                    else {
                        unset( $rDate[Util::$LCparams][Util::$TZID] );
                    }
                }
                elseif( isset( $tzId ) && ! Util::isOffset( $tzId ) ) {
                    $rDate[Util::$LCparams][Util::$TZID] = $tzId;
                }
            }
        }
        elseif( isset( $rDate[Util::$LCparams][Util::$TZID] ) &&
            ! empty( $rDate[Util::$LCparams][Util::$TZID] ) ) {
            if( Util::isOffset( $rDate[Util::$LCparams][Util::$TZID] ) ) {
                $arrTimestamp[Util::$LCtz] = $rDate[Util::$LCparams][Util::$TZID];
                unset( $rDate[Util::$LCparams][Util::$TZID] );
                if( isset( $tzId ) && ! empty( $tzId ) && ! Util::isOffset( $tzId ) ) {
                    $rDate[Util::$LCparams][Util::$TZID] = $tzId;
                }
            }
        }
        $rDate[Util::$LCvalue] = Util::timestamp2date( $arrTimestamp, $parno );
        return $parno;
    }

    /**
     * Ensure internal date (format) with parameters based on input string date
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.6 - 2015-11-19
     * @param array  $rDate
     * @param string $strDate
     * @param mixed  $params
     * @param string $tzId
     * @param bool   $localtime
     * @return int
     * @access private
     * @static
     */
    private static function setDateIsStringDate( array & $rDate, $strDate, $params, $tzId, $localtime ) {
        if( $localtime ) {
            unset( $params[Util::$LCvalue], $params[Util::$TZID] );
        }
        elseif( ! isset( $params[Util::$TZID] ) && ! empty( $tzId )) {
            $params[Util::$TZID] = $tzId;
        }
        $rDate[Util::$LCparams] = Util::setParams( $params, Util::$DEFAULTVALUEDATETIME );
        $parno = Util::existRem(
            $rDate[Util::$LCparams],
            Util::$VALUE,
            Util::$DATE_TIME,
            7
        );
        $parno = Util::existRem(
            $rDate[Util::$LCparams],
            Util::$VALUE,
            Util::$DATE,
            3,
            $parno,
            $parno
        );
        $rDate[Util::$LCvalue]  = Util::strDate2ArrayDate( $strDate, $parno );
        if( 3 == $parno ) {
            unset( $rDate[Util::$LCvalue][Util::$LCtz],
                $rDate[Util::$LCparams][Util::$TZID]
            );
        }
        unset( $rDate[Util::$LCvalue][Util::$UNPARSEDTEXT] );
        if( isset( $rDate[Util::$LCvalue][Util::$LCtz] )) {
            if( Util::isOffset( $rDate[Util::$LCvalue][Util::$LCtz] )) {
                $rDate[Util::$LCvalue] = Util::ensureArrDatetime($rDate, $rDate[Util::$LCvalue][Util::$LCtz], 7 );
                unset( $rDate[Util::$LCvalue][Util::$UNPARSEDTEXT],
                    $rDate[Util::$LCparams][Util::$TZID]
                );
            }
            else {
                $rDate[Util::$LCparams][Util::$TZID] = $rDate[Util::$LCvalue][Util::$LCtz];
                unset( $rDate[Util::$LCvalue][Util::$LCtz] );
            }
        }
        elseif( isset( $rDate[Util::$LCparams][Util::$TZID] ) &&
            Util::isOffset( $rDate[Util::$LCparams][Util::$TZID] )) {
            $rDate[Util::$LCvalue] = Util::ensureArrDatetime( $rDate, $rDate[Util::$LCparams][Util::$TZID], 7 );
            unset( $rDate[Util::$LCvalue][Util::$UNPARSEDTEXT],
                $rDate[Util::$LCparams][Util::$TZID]
            );
        }
        return $parno;
    }

    /**
     * Ensure internal date (format) with parameters based on all args date
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.6 - 2015-11-19
     * @param array  $rDate
     * @param mixed  $year
     * @param mixed  $month
     * @param int    $day
     * @param int    $hour
     * @param int    $min
     * @param int    $sec
     * @param string $tz
     * @param array  $params
     * @param string $tzId
     * @param bool   $localtime
     * @return int
     * @access private
     * @static
     */
    private static function setDateIsAllArgsDate(
        array & $rDate,
        $year,
        $month     = null,
        $day       = null,
        $hour      = null,
        $min       = null,
        $sec       = null,
        $tz        = null,
        $params    = null,
        $tzId      = null,
        $localtime = false
    ) {
        if( 100 > $year ) {
            $year += 2000;
        }
        if( is_array( $params )) {
            $rDate[Util::$LCparams] = Util::setParams( $params, Util::$DEFAULTVALUEDATETIME );
        }
        elseif( is_array( $tz )) {
            $rDate[Util::$LCparams] = Util::setParams( $tz, Util::$DEFAULTVALUEDATETIME );
            $tz                     = false;
        }
        elseif( is_array( $hour )) {
            $rDate[Util::$LCparams] = Util::setParams( $hour, Util::$DEFAULTVALUEDATETIME );
            $hour                   = $min = $sec = $tz = false;
        }
        if( $localtime ) {
            unset ( $rDate[Util::$LCparams][Util::$LCvalue],
                $rDate[Util::$LCparams][Util::$TZID]
            );
        }
        elseif( ! isset( $tz ) && ! isset( $rDate[Util::$LCparams][Util::$TZID] ) && ! empty( $tzId )) {
            $rDate[Util::$LCparams][Util::$TZID] = $tzId;
        }
        elseif( isset( $tz ) && Util::isOffset( $tz )) {
            unset( $rDate[Util::$LCparams][Util::$TZID] );
        }
        elseif( isset( $rDate[Util::$LCparams][Util::$TZID] ) &&
            Util::isOffset( $rDate[Util::$LCparams][Util::$TZID] )) {
            $tz = $rDate[Util::$LCparams][Util::$TZID];
            unset( $rDate[Util::$LCparams][Util::$TZID] );
        }
        if( ! isset( $rDate[Util::$LCparams] )) {
            $rDate[Util::$LCparams] = [];
        }
        $parno  = Util::existRem( $rDate[Util::$LCparams], Util::$VALUE, Util::$DATE, 3 );
        $returnValue = ( Util::isOffset( $tz )) ? 7 : 6;
        $parno  = Util::existRem( $rDate[Util::$LCparams], Util::$VALUE, Util::$DATE_TIME, $returnValue, $parno, $parno );
        $rDate[Util::$LCvalue] = [
            Util::$LCYEAR  => $year,
            Util::$LCMONTH => $month,
            Util::$LCDAY   => $day,
        ];
        if( 3 != $parno ) {
            $rDate[Util::$LCvalue][Util::$LCHOUR] = ( $hour ) ? $hour : Util::$ZERO;
            $rDate[Util::$LCvalue][Util::$LCMIN]  = ( $min )  ? $min  : Util::$ZERO;
            $rDate[Util::$LCvalue][Util::$LCSEC]  = ( $sec )  ? $sec  : Util::$ZERO;
            if( ! empty( $tz )) {
                $rDate[Util::$LCvalue][Util::$LCtz] = $tz;
            }
            $strDate = Util::date2strdate( $rDate[Util::$LCvalue], $parno );
            if( ! empty( $tz ) && ! Util::isOffset( $tz )) {
                $strDate .= ( Util::$Z == $tz ) ? $tz : ' ' . $tz;
            }
            $rDate[Util::$LCvalue] = Util::strDate2ArrayDate( $strDate, $parno );
            unset( $rDate[Util::$LCvalue][Util::$UNPARSEDTEXT] );
            if( isset( $rDate[Util::$LCvalue][Util::$LCtz] )) {
                if( Util::isOffset( $rDate[Util::$LCvalue][Util::$LCtz] )) {
                    $rDate[Util::$LCvalue] = Util::ensureArrDatetime( $rDate, $rDate[Util::$LCvalue][Util::$LCtz], 7 );
                    unset( $rDate[Util::$LCvalue][Util::$UNPARSEDTEXT], $rDate[Util::$LCparams][Util::$TZID] );
                }
                else {
                    $rDate[Util::$LCparams][Util::$TZID] = $rDate[Util::$LCvalue][Util::$LCtz];
                    unset( $rDate[Util::$LCvalue][Util::$LCtz] );
                }
            }
            elseif(      isset( $rDate[Util::$LCparams][Util::$TZID] ) &&
                Util::isOffset( $rDate[Util::$LCparams][Util::$TZID] )) {
                $rDate[Util::$LCvalue] = Util::ensureArrDatetime( $rDate, $rDate[Util::$LCparams][Util::$TZID], 7 );
                unset( $rDate[Util::$LCvalue][Util::$UNPARSEDTEXT],  $rDate[Util::$LCparams][Util::$TZID] );
            }
        }
        return $parno;
    }

    /**
     * Check value=DATE and timezone
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.6 - 2015-11-19
     * @param array  $rDate,
     * @param int    $parno
     * @access private
     * @static
     */
    private static function setDateCheckValueAndTimezone( array & $rDate, $parno ) {
        if(( 3 == $parno ) || Util::isParamsValueSet( $rDate, Util::$DATE )) {
            $rDate[Util::$LCparams][Util::$VALUE] = Util::$DATE;
            unset(
                $rDate[Util::$LCvalue][Util::$LCHOUR],
                $rDate[Util::$LCvalue][Util::$LCMIN],
                $rDate[Util::$LCvalue][Util::$LCSEC],
                $rDate[Util::$LCvalue][Util::$LCtz],
                $rDate[Util::$LCparams][Util::$TZID]
            );
        }
        elseif( isset( $rDate[Util::$LCparams][Util::$TZID] )) {
            if(( 0 == strcasecmp( Util::$UTC, $rDate[Util::$LCparams][Util::$TZID] )) ||
                ( 0 == strcasecmp( Util::$GMT, $rDate[Util::$LCparams][Util::$TZID] ))) {
                $rDate[Util::$LCvalue][Util::$LCtz] = Util::$Z;
                unset( $rDate[Util::$LCparams][Util::$TZID] );
            }
            else {
                unset( $rDate[Util::$LCvalue][Util::$LCtz] );
            }
        }
        elseif( isset( $rDate[Util::$LCvalue][Util::$LCtz] )) {
            if(( 0 == strcasecmp( Util::$UTC, $rDate[Util::$LCvalue][Util::$LCtz] )) ||
                ( 0 == strcasecmp( Util::$GMT, $rDate[Util::$LCvalue][Util::$LCtz] ))) {
                $rDate[Util::$LCvalue][Util::$LCtz] = Util::$Z;
            }
            if( Util::$Z != $rDate[Util::$LCvalue][Util::$LCtz] ) {
                $rDate[Util::$LCparams][Util::$TZID] = $rDate[Util::$LCvalue][Util::$LCtz];
                unset( $rDate[Util::$LCvalue][Util::$LCtz] );
            }
            else {
                unset( $rDate[Util::$LCparams][Util::$TZID] );
            }
        }
    }


    /**
     * Return input (UTC) date to internal date with parameters
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-02-17
     * @param mixed $year
     * @param mixed $month
     * @param int   $day
     * @param int   $hour
     * @param int   $min
     * @param int   $sec
     * @param array $params
     * @return array
     * @static
     */
    public static function setDate2(
        $year,
        $month  = null,
        $day    = null,
        $hour   = null,
        $min    = null,
        $sec    = null,
        $params = null
    ) {
        $rDate = [];
        Util::strDate2arr( $year );
        switch( true) {
            case ( $year instanceof DateTime ) :
                $parno = 7; // ensure UTC
                $year->setTimezone((new DateTimeZone( Util::$UTC )));
                Util::EnsureParamValueIsDateTime( $month );
                $rDate = self::dateTime2Arr( $year, $month, false, $parno );
                break;
            case ( Util::isArrayDate( $year )) :
                Util::EnsureParamValueIsDateTime( $month );
                Util::setDate2IsArrayDate( $rDate, $year, $month );
                break;
            case ( Util::isArrayTimestampDate( $year )) :
                Util::EnsureParamValueIsDateTime( $month );
                Util::setDate2IsArrayTimestampDate( $rDate, $year, $month );
                break;
            case ( is_string($year ) && ( 8 <= strlen( trim((string) $year )))) :
                Util::EnsureParamValueIsDateTime( $month );
                Util::setDate2IsStringDate( $rDate, $year, $month );
                break;
            default :
                Util::EnsureParamValueIsDateTime( $params );
                Util::setDate2IsAllArgsDate( $rDate, $year, $month, $day, $hour, $min, $sec, $params );
                break;
        }
        Util::setDate2CheckValueAndUtcTimezone( $rDate );
        return $rDate;
    }

    /**
     * Ensure param Value = Date-Time
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.6 - 2015-11-21
     * @param null|array $params
     * @return array
     * @access private
     * @static
     */
    private static function EnsureParamValueIsDateTime( $params = null ) {
        if( is_array( $params )) {
            $params[Util::$VALUE] = Util::$DATE_TIME;
        }
        else {
            $params = Util::$DEFAULTVALUEDATETIME;
        }
        return $params;
    }

    /**
     * Ensure internal date (format) with parameters based on input array date
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.6 - 2015-11-19
     * @param array  $rDate
     * @param mixed  $arrDate
     * @param mixed  $params
     * @access private
     * @static
     */
    private static function setDate2IsArrayDate( array & $rDate, $arrDate, $params ) {
        $rDate[Util::$LCvalue] = Util::chkDateArr( $arrDate, 7 );
        if( isset( $rDate[Util::$LCvalue][Util::$LCYEAR] ) &&
            ( 100 > $rDate[Util::$LCvalue][Util::$LCYEAR] )) {
            $rDate[Util::$LCvalue][Util::$LCYEAR] += 2000;
        }
        $rDate[Util::$LCparams] = Util::setParams( $params );
        $tzId = null;
        if(          isset( $rDate[Util::$LCvalue][Util::$LCtz] ) &&
            Util::isOffset( $rDate[Util::$LCvalue][Util::$LCtz] )) {
            $tzId = $rDate[Util::$LCvalue][Util::$LCtz];
        }
        elseif( isset( $rDate[Util::$LCparams][Util::$TZID] ) &&
            Util::isOffset( $rDate[Util::$LCparams][Util::$TZID] )) {
            $tzId = $rDate[Util::$LCparams][Util::$TZID];
        }
        if( ! empty( $tzId ) && ( Util::$Z != $tzId ) && Util::isOffset( $tzId )) {
            $rDate[Util::$LCvalue] = Util::ensureArrDatetime( $rDate, $tzId, 7 );
            unset( $rDate[Util::$LCvalue][Util::$UNPARSEDTEXT] );
        }
    }

    /**
     * Ensure internal date (format) with parameters based on input timestamp date
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.6 - 2015-11-19
     * @param array  $rDate
     * @param mixed  $arrTimestamp
     * @param mixed  $params
     * @access private
     * @static
     */
    private static function setDate2IsArrayTimestampDate( array & $rDate, $arrTimestamp, $params ) {
        if(            isset( $arrTimestamp[Util::$LCtz] ) &&
            ! Util::isOffset( $arrTimestamp[Util::$LCtz] )) {
            $arrTimestamp[Util::$LCtz] = Util::$UTC;
        }
        elseif(      isset( $rDate[Util::$LCparams][Util::$TZID] ) &&
            Util::isOffset( $rDate[Util::$LCparams][Util::$TZID] )) {
            $arrTimestamp[Util::$LCtz] = $rDate[Util::$LCparams][Util::$TZID];
        }
        else {
            $arrTimestamp[Util::$LCtz] = Util::$UTC;
        }
        $rDate[Util::$LCvalue]  = Util::timestamp2date( $arrTimestamp, 7 );
        $rDate[Util::$LCparams] = Util::setParams( $params );
    }

    /**
     * Ensure internal date (format) with parameters based on input string date
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.6 - 2015-11-19
     * @param array  $rDate
     * @param mixed  $strDate
     * @param mixed  $params
     * @access private
     * @static
     */
    private static function setDate2IsStringDate( array & $rDate, $strDate, $params ) {
        $rDate[Util::$LCvalue] = Util::strDate2ArrayDate( $strDate, 7 );
        unset( $rDate[Util::$LCvalue][Util::$UNPARSEDTEXT] );
        $rDate[Util::$LCparams] = Util::setParams( $params );
        if((  ! isset( $rDate[Util::$LCvalue][Util::$LCtz] ) ||
                empty( $rDate[Util::$LCvalue][Util::$LCtz] )) &&
            isset( $rDate[Util::$LCparams][Util::$TZID] ) &&
            Util::isOffset( $rDate[Util::$LCparams][Util::$TZID] )) {
            $rDate[Util::$LCvalue] = Util::ensureArrDatetime( $rDate, $rDate[Util::$LCparams][Util::$TZID], 7 );
            unset( $rDate[Util::$LCvalue][Util::$UNPARSEDTEXT] );
        }
    }

    /**
     * Ensure internal date (format) with parameters based on input string date
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.6 - 2015-11-19
     * @param array  $rDate
     * @param mixed $year
     * @param mixed $month
     * @param int   $day
     * @param int   $hour
     * @param int   $min
     * @param int   $sec
     * @param array $params
     * @access private
     * @static
     */
    private static function setDate2IsAllArgsDate(
        array & $rDate,
        $year,
        $month  = null,
        $day    = null,
        $hour   = null,
        $min    = null,
        $sec    = null,
        $params = null
    ) {
        if( 100 > $year ) {
            $year += 2000;
        }
        $rDate[Util::$LCvalue] = [
            Util::$LCYEAR  => $year,
            Util::$LCMONTH => $month,
            Util::$LCDAY   => $day,
            Util::$LCHOUR  => $hour,
            Util::$LCMIN   => $min,
            Util::$LCSEC   => $sec,
        ];
        $rDate[Util::$LCparams] = Util::setParams( $params );
    }

    /**
     * Check value=DATE and UTC timezone
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.6 - 2015-11-19
     * @param array  $rDate,
     * @access private
     * @static
     */
    private static function setDate2CheckValueAndUtcTimezone( array & $rDate ) {
        unset( $rDate[Util::$LCparams][Util::$VALUE], $rDate[Util::$LCparams][Util::$TZID] );
        if( ! isset( $rDate[Util::$LCvalue][Util::$LCHOUR] )) {
            $rDate[Util::$LCvalue][Util::$LCHOUR] = 0;
        }
        if( ! isset( $rDate[Util::$LCvalue][Util::$LCMIN] )) {
            $rDate[Util::$LCvalue][Util::$LCMIN] = 0;
        }
        if( ! isset( $rDate[Util::$LCvalue][Util::$LCSEC] )) {
            $rDate[Util::$LCvalue][Util::$LCSEC] = 0;
        }
        $rDate[Util::$LCvalue][Util::$LCtz] = Util::$Z;
    }

    /**
     * Return date-array (in internal format) for an DateTime
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.7 - 2018-11-19
     * @param DateTime $datetime
     * @param array    $params
     * @param bool     $localtime
     * @param int      $parno
     * @return array
     * @static
     */
    public static function dateTime2Arr(
        DateTime $datetime,
        $params    = null,
        $localtime = null,
        & $parno   = null
    ) {
        static $YMDHISe = 'Y-m-d H:i:s e';
        $tDate = $datetime->format( $YMDHISe );
        self::strDate2arr( $tDate );
        $rDate = [
            Util::$LCvalue  => $tDate,
            Util::$LCparams => Util::setParams( $params, Util::$DEFAULTVALUEDATETIME )
        ];
        if( $localtime ) {
            unset( $rDate[Util::$LCvalue][Util::$LCtz] );
        }
        unset( $rDate[Util::$LCparams][Util::$TZID] ); // tz from DateTime
        $parno = ( isset( $rDate[Util::$LCparams][Util::$VALUE] ) &&
                 ( self::$DATE == $rDate[Util::$LCparams][Util::$VALUE] ))
            ? 3 : 7;
        Util::existRem( $rDate[Util::$LCparams], Util::$VALUE, Util::$DATE_TIME );
        return $rDate;
    }

    /**
     * Return string formatted DateTime, if offset set then timezone UTC
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.7 - 2018-11-22
     * @param DateTime $datetime
     * @return string
     * @static
     */
    public static function dateTime2Str( $datetime ) {
        static $UTC     = 'UTC';
        static $YMDHISe = 'Y-m-d H:i:s e';
        if( Util::dateTimeHasOffset( $datetime )) {
            $datetime->setTimezone( new DateTimeZone( $UTC ));
        }
        return $datetime->format( $YMDHISe );
    }

    /**
     * Return bool true if datetime har offset timezone
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.9 - 2019-04-09
     * @param DateTime $datetime
     * @return bool
     * @static
     */
    public static function dateTimeHasOffset( $datetime ) {
        $tzName = $datetime->getTimezone()->getName();
        return (( false != strpos( $tzName, Util::$COLON )) || Util::isOffset( $tzName ));
    }

    /**
     * Return array (in internal format) for an input date-time/date array (keyed or unkeyed)
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.1 - 2018-12-01
     * @param array $datetime
     * @param int   $parno default null, 3: DATE(Ymd), 6: YmdHis, 7: YmdHis + offset/timezone
     * @return array
     * @static
     */
    public static function chkDateArr( $datetime, $parno = null ) {
        static $PLUS4ZERO  = '+0000';
        static $MINUS4ZERO = '-0000';
        static $PLUS6ZERO  = '+000000';
        static $MINUS6ZERO = '-000000';
        $output = [];
        if(( is_null( $parno ) || ( 6 <= $parno )) && isset( $datetime[3] ) && ! isset( $datetime[4] )) {
            $temp        = $datetime[3];  // Y-m-d with tz
            $datetime[3] = $datetime[4] = $datetime[5] = 0;
            $datetime[6] = $temp;
        }
        foreach( $datetime as $dateKey => $datePart ) {
            switch( $dateKey ) {
                case Util::$ZERO:
                case Util::$LCYEAR :
                    $output[Util::$LCYEAR] = (int) $datePart;
                    break;
                case '1':
                case Util::$LCMONTH :
                    $output[Util::$LCMONTH] = (int) $datePart;
                    break;
                case '2':
                case Util::$LCDAY :
                    $output[Util::$LCDAY] = (int) $datePart;
                    break;
            }
            if( 3 != $parno ) {
                switch( $dateKey ) {
                    case Util::$ZERO:
                    case '1':
                    case '2':
                        break;
                    case '3':
                    case Util::$LCHOUR:
                        $output[Util::$LCHOUR] = (int) $datePart;
                        break;
                    case '4':
                    case Util::$LCMIN :
                        $output[Util::$LCMIN] = (int) $datePart;
                        break;
                    case '5':
                    case Util::$LCSEC :
                        $output[Util::$LCSEC] = (int) $datePart;
                        break;
                    case '6':
                    case Util::$LCtz  :
                        $output[Util::$LCtz] = $datePart;
                        break;
                }
            }
        }
        if( 3 != $parno ) {
            if( ! isset( $output[Util::$LCHOUR] )) {
                $output[Util::$LCHOUR] = 0;
            }
            if( ! isset( $output[Util::$LCMIN] )) {
                $output[Util::$LCMIN] = 0;
            }
            if( ! isset( $output[Util::$LCSEC] )) {
                $output[Util::$LCSEC] = 0;
            }
            if( isset( $output[Util::$LCtz] ) &&
                (( $PLUS4ZERO  == $output[Util::$LCtz] ) ||
                 ( $MINUS4ZERO == $output[Util::$LCtz] ) ||
                 ( $PLUS6ZERO  == $output[Util::$LCtz] ) ||
                 ( $MINUS6ZERO == $output[Util::$LCtz] ))) {
                $output[Util::$LCtz] = Util::$Z;
            }
        }
        return $output;
    }

    /**
     * Return iCal formatted string for (internal array) date/date-time
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.22.23 - 2017-02-24
     * @param array $datetime
     * @param int   $parno default 6
     * @return string
     * @static
     */
    public static function date2strdate( $datetime, $parno = null ) {
        static $SECONDS = ' seconds';
        static $YMDYHIS = 'Ymd\THis';
        static $UTCARR  = null;
        if( empty( $UTCARR )) {
            $UTCARR = [ Util::$Z, Util::$UTC, Util::$GMT ];
        }
        if( ! isset( $datetime[Util::$LCYEAR] ) &&
            ! isset( $datetime[Util::$LCMONTH] ) &&
            ! isset( $datetime[Util::$LCDAY] ) &&
            ! isset( $datetime[Util::$LCHOUR] ) &&
            ! isset( $datetime[Util::$LCMIN] ) &&
            ! isset( $datetime[Util::$LCSEC] )) {
            return null;
        }
        if( is_null( $parno )) {
            $parno = 6;
        }
        foreach( $datetime as $dkey => & $dvalue ) {
            if( Util::$LCtz != $dkey ) {
                $dvalue = (int) $dvalue;
            }
        }
        $output = Util::getYMDString( $datetime );
        if( 3 == $parno ) {
            return $output;
        }
        if( ! isset( $datetime[Util::$LCHOUR] )) {
            $datetime[Util::$LCHOUR] = 0;
        }
        if( ! isset( $datetime[Util::$LCMIN] )) {
            $datetime[Util::$LCMIN] = 0;
        }
        if( ! isset( $datetime[Util::$LCSEC] )) {
            $datetime[Util::$LCSEC] = 0;
        }
        $output .= Util::$T . Util::getHisString( $datetime );
        if( isset( $datetime[Util::$LCtz] )) {
            $datetime[Util::$LCtz] = trim( $datetime[Util::$LCtz] );
            switch( true ) {
                case ( empty( $datetime[Util::$LCtz] )) :
                    break;
                case ( in_array( strtoupper( $datetime[Util::$LCtz] ), $UTCARR )) :
                    $output .= Util::$Z;
                    break;
                case ( Util::isOffset( $datetime[Util::$LCtz] )) :
                    $offset = Util::tz2offset( $datetime[Util::$LCtz] );
                    try {
                        $timezone = new DateTimeZone( Util::$UTC );
                        $d        = new DateTime( $output, $timezone );
                        if( 0 != $offset ) { // adjust för offset
                            $d->modify( $offset . $SECONDS );
                        }
                        $output = $d->format( $YMDYHIS );
                    }
                    catch( Exception $e ) {
                        $output = date(
                            $YMDYHIS,
                            mktime( $datetime[Util::$LCHOUR],
                                    $datetime[Util::$LCMIN],
                                  ( $datetime[Util::$LCSEC] - $offset ),
                                    $datetime[Util::$LCMONTH],
                                    $datetime[Util::$LCDAY],
                                    $datetime[Util::$LCYEAR]
                            )
                        );
                    }
                    $output .= Util::$Z;
                    break;
                default :
                    $output .= $datetime[Util::$LCtz];
                    break;
            } // end switch
        }
        return $output;
    }

    /**
     * Return bool true if input contains a date/time (in array format)
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.16.24 - 2013-07-02
     * @param mixed $input
     * @return bool
     * @static
     */
    public static function isArrayDate( $input ) {
        if( ! is_array( $input ) ||
            isset( $input[Util::$LCWEEK] ) ||
            isset( $input[Util::$LCTIMESTAMP] ) ||
            ( 3 > count( $input ))) {
            return false;
        }
        if( 7 == count( $input )) {
            return true;
        }
        if( isset( $input[Util::$LCYEAR] ) &&
            isset( $input[Util::$LCMONTH] ) &&
            isset( $input[Util::$LCDAY] )) {
            return checkdate((int) $input[Util::$LCMONTH], (int) $input[Util::$LCDAY], (int) $input[Util::$LCYEAR] );
        }
        if( isset( $input[Util::$LCDAY] ) ||
            isset( $input[Util::$LCHOUR] ) ||
            isset( $input[Util::$LCMIN] ) ||
            isset( $input[Util::$LCSEC] )) {
            return false;
        }
        if(( 0 == $input[0] ) || ( 0 == $input[1] ) || ( 0 == $input[2] )) {
            return false;
        }
        if(( 1970 > $input[0] ) || ( 12 < $input[1] ) || ( 31 < $input[2] )) {
            return false;
        }
        if(( isset( $input[0] ) && isset( $input[1] ) && isset( $input[2] )) &&
            checkdate((int) $input[1],
                      (int) $input[2],
                      (int) $input[0]
            )) {
            return true;
        }
        $input = Util::strDate2ArrayDate( $input[1] . Util::$L . $input[2] . Util::$L . $input[0], 3 ); //  m - d - Y
        if( isset( $input[Util::$LCYEAR] ) && isset( $input[Util::$LCMONTH] ) && isset( $input[Util::$LCDAY] )) {
            return checkdate((int) $input[Util::$LCMONTH], (int) $input[Util::$LCDAY], (int) $input[Util::$LCYEAR] );
        }
        return false;
    }

    /**
     * Return bool true if input array contains a (keyed) timestamp date
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.7 - 2018-11-23
     * @param mixed $input
     * @return bool
     * @static
     */
    public static function isArrayTimestampDate( $input ) {
        return ( is_array( $input ) && isset( $input[Util::$LCTIMESTAMP] ));
    }

    /**
     * Return bool true if input string contains (trailing) UTC/iCal offset
     *
     * An offset is one of [+/-]NNNN, [+/-]NN:NN, [+/-]NNNNNN, [+/-]NN:NN:NN
     * @param string $input
     * @return bool
     * @static
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.7 - 2018-11-23
     */
    public static function isOffset( $input ) {
        $input = trim((string) $input );
        if( Util::$Z == substr( $input, -1 )) {
            return true;
        }
        if( false != strpos( $input, Util::$COLON )) {
            $input = str_replace( Util::$COLON, Util::$SP0, $input );
        }
        $strlen = strlen( $input );
        if(( 7 <= $strlen ) &&
            ( in_array( substr( $input, -7, 1 ), Util::$PLUSMINUSARR )) &&
            ctype_digit( substr( $input, -6 ))) {
            return true;
        }
        if(( 5 <= $strlen ) &&
            ( in_array( substr( $input, -5, 1 ), Util::$PLUSMINUSARR )) &&
            ctype_digit( substr( $input, -4 ))) {
            return true;
        }
        return false;
    }

    /**
     * Convert a date from string to (internal, keyed) array format, return true on success
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.7 - 2018-11-19
     * @param mixed $date
     * @return bool, true on success
     * @static
     */
    public static function strDate2arr( & $date ) {
        static $ET = [ ' ', 't', 'T' ];
        if( is_array( $date )) {
            return false;
        }
        if( ! is_string( $date )) {
            return false;
        }
        if( 5 > strlen((string) $date )) {
            return false;
        }
        $work = $date;
        if( 2 == substr_count( $work, Util::$MINUS )) {
            $work = str_replace( Util::$MINUS, null, $work );
        }
        if( 2 == substr_count( $work, Util::$L )) {
            $work = str_replace( Util::$L, null, $work );
        }
        if( ! ctype_digit( substr( $work, 0, 8 ))) {
            return false;
        }
        $temp = [
            Util::$LCYEAR  => (int) substr( $work, 0, 4 ),
            Util::$LCMONTH => (int) substr( $work, 4, 2 ),
            Util::$LCDAY   => (int) substr( $work, 6, 2 ),
        ];
        if( ! checkdate( $temp[Util::$LCMONTH], $temp[Util::$LCDAY], $temp[Util::$LCYEAR] )) {
            return false;
        }
        if( 8 == strlen( $work )) {
            $date = $temp;
            return true;
        }
        if( in_array( $work[8], $ET )) {
            $work = substr( $work, 9 );
        }
        elseif( ctype_digit( $work[8] )) {
            $work = substr( $work, 8 );
        }
        else {
            return false;
        }
        if( 2 == substr_count( $work, Util::$COLON )) {
            $work = str_replace( Util::$COLON, null, $work );
        }
        if( ! ctype_digit( substr( $work, 0, 4 ))) {
            return false;
        }
        $temp[Util::$LCHOUR] = substr( $work, 0, 2 );
        $temp[Util::$LCMIN]  = substr( $work, 2, 2 );
        if((( 0 > $temp[Util::$LCHOUR] ) || ( $temp[Util::$LCHOUR] > 23 )) ||
           (( 0 > $temp[Util::$LCMIN] )  || ( $temp[Util::$LCMIN] > 59 ))) {
            return false;
        }
        if( ctype_digit( substr( $work, 4, 2 ))) {
            $temp[Util::$LCSEC] = substr( $work, 4, 2 );
            if(( 0 > $temp[Util::$LCSEC] ) || ( $temp[Util::$LCSEC] > 59 )) {
                return false;
            }
            $len = 6;
        }
        else {
            $temp[Util::$LCSEC] = 0;
            $len                = 4;
        }
        if( $len < strlen( $work )) {
            $temp[Util::$LCtz] = trim( substr( $work, 6 ));
        }
        $date = $temp;
        return true;
    }

    /**
     * Return string date-time/date as array (in internal format, keyed)
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.1 - 2018-12-01
     * Modified to also return original string value by Yitzchok Lavi <icalcreator@onebigsystem.com>
     * @param string $datetime
     * @param int    $parno default false
     * @param mixed  $wtz   default null
     * @return array
     * @static
     */
    public static function strDate2ArrayDate(
        $datetime,
        $parno = null,
        $wtz   = null
    ) {
        static $SECONDS = ' seconds';
        $unparseddatetime = $datetime;
        $datetime         = (string) trim( $datetime );
        $tz               = null;
        $offset           = 0;
        $tzSts            = false;
        $len              = strlen( $datetime );
        if( Util::$Z == substr( $datetime, -1 )) {
            $tz       = Util::$Z;
            $datetime = trim( substr( $datetime, 0, ( $len - 1 )));
            $tzSts    = true;
        }
        else {
            foreach( [ -5, -6, -7, -9] as $cnt ) {
                if( Util::isOffset( substr( $datetime, $cnt ))) {
                    $tz       = substr( $datetime, $cnt );
                    $datetime = trim( substr( $datetime, 0, ( $cnt + $len )));
                    break;
                }
            }
        }
        if( empty( $tz ) &&
            empty( $wtz ) &&
            ctype_digit( substr( $datetime, 0, 4 )) &&
            ctype_digit( substr( $datetime, -2, 2 )) &&
            Util::strDate2arr( $datetime )) { // array
            $output = (array) $datetime;
            if( ! empty( $tz )) {
                $output[Util::$LCtz] = Util::$Z;
            }
            $output[Util::$UNPARSEDTEXT] = $unparseddatetime;
            return $output;
        }
        elseif( empty( $tz )) {
            $tx  = 0;  //  find any TRAILING timezone or offset
            $len = strlen( $datetime );
            for( $cx = -1; $cx > ( 9 - $len ); $cx-- ) {
                $char = substr( $datetime, $cx, 1 );
                if(( Util::$SP1 == $char ) || ctype_digit( $char )) {
                    break;
                }       // if exists, tz ends here.. . ?
                else {
                    $tx--;
                }      // tz length counter
            }
            if( 0 > $tx ) {  // if any timezone or offset found
                $tz       = substr( $datetime, $tx );
                $datetime = trim( substr( $datetime, 0, $len + $tx ));
            }
            if(( ctype_digit( substr( $datetime, 0, 8 )) &&
                    ( Util::$T == $datetime[8] ) &&
                    ctype_digit( substr( $datetime, -6, 6 ))) ||
                ( ctype_digit( substr( $datetime, 0, 14 )))) {
                $tzSts = true;
            }
        }
        if( empty( $tz ) && ! empty( $wtz )) {
            $tz = $wtz;
        }
        if( 3 == $parno ) {
            $tz = null;
        }
        if( ! empty( $tz )) { // tz set
            if(( Util::$Z != $tz ) && ( Util::isOffset( $tz ))) {
                $offset = (string) Util::tz2offset( $tz ) * -1;
                $tz     = Util::$UTC;
                $tzSts  = true;
            }
            elseif( ! empty( $wtz )) {
                $tzSts = true;
            }
            $tz = trim( $tz );
            if(( 0 == strcasecmp( Util::$Z, $tz )) ||
               ( 0 == strcasecmp( Util::$GMT, $tz ))) {
                $tz = Util::$UTC;
            }
            if( 0 < substr_count( $datetime, Util::$MINUS )) {
                $datetime = str_replace( Util::$MINUS, Util::$L, $datetime );
            }
            try {
                $timezone = new DateTimeZone( $tz );
                $d        = new DateTime( $datetime, $timezone );
                if( 0 != $offset )  // adjust for offset
                {
                    $d->modify( $offset . $SECONDS );
                }
                $datestring = $d->format( Util::$YMDHIS3 );
                unset( $d );
            }
            catch( Exception $e ) {
                $datestring = date( Util::$YMDHIS3, strtotime( $datetime ));
            }
        } // end if( ! empty( $tz ))
        else {
            $datestring = date( Util::$YMDHIS3, strtotime( $datetime ));
        }
        if( Util::$UTC == $tz ) {
            $tz = Util::$Z;
        }
        $d      = explode( Util::$MINUS, $datestring );
        $output = [
            Util::$LCYEAR  => (int) $d[0],
            Util::$LCMONTH => (int) $d[1],
            Util::$LCDAY   => (int) $d[2],
        ];
        if( ! empty( $parno ) || ( 3 != $parno )) { // parno is set to 6 or 7
            $output[Util::$LCHOUR] = (int) $d[3];
            $output[Util::$LCMIN]  = (int) $d[4];
            $output[Util::$LCSEC]  = (int) $d[5];
            if(( $tzSts || ( 7 == $parno )) && ! empty( $tz )) {
                $output[Util::$LCtz] = $tz;
            }
        }
        // return original string in the array in case strtotime failed to make sense of it
        $output[Util::$UNPARSEDTEXT] = $unparseddatetime;
        return $output;
    }

    /**
     * Return string/array timestamp(+ offset/timezone (default UTC)) as array (in internal format, keyed).
     *
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.21.11 - 2015-03-07
     * @param mixed  $timestamp
     * @param int    $parno
     * @param string $wtz
     * @return array
     * @static
     */
    public static function timestamp2date( $timestamp, $parno = 6, $wtz = null ) {
        static $FMTTIMESTAMP = '@%s';
        static $SPSEC        = ' seconds';
        if( is_array( $timestamp )) {
            $tz        = ( isset( $timestamp[Util::$LCtz] )) ? $timestamp[Util::$LCtz] : $wtz;
            $timestamp = $timestamp[Util::$LCTIMESTAMP];
        }
        $tz     = ( isset( $tz )) ? $tz : $wtz;
        $offset = 0;
        if( empty( $tz ) || ( Util::$Z == $tz ) || ( 0 == strcasecmp( Util::$GMT, $tz ))) {
            $tz = Util::$UTC;
        }
        elseif( Util::isOffset( $tz )) {
            $offset = Util::tz2offset( $tz );
        }
        try {
            $timestamp = sprintf( $FMTTIMESTAMP, $timestamp );
            $d         = new DateTime( $timestamp );     // set UTC date
            if( 0 != $offset )                           // adjust for offset
            {
                $d->modify( $offset . $SPSEC );
            }
            elseif( Util::$UTC != $tz ) {
                $d->setTimezone( new DateTimeZone( $tz ));
            } // convert to local date
            $date = $d->format( Util::$YMDHIS3 );
        }
        catch( Exception $e ) {
            $date = date( Util::$YMDHIS3, $timestamp );
        }
        $date   = explode( Util::$MINUS, $date );
        $output = [
            Util::$LCYEAR  => $date[0],
            Util::$LCMONTH => $date[1],
            Util::$LCDAY   => $date[2],
        ];
        if( 3 != $parno ) {
            $output[Util::$LCHOUR] = $date[3];
            $output[Util::$LCMIN]  = $date[4];
            $output[Util::$LCSEC]  = $date[5];
            if(( Util::$UTC == $tz ) || ( 0 == $offset )) {
                $output[Util::$LCtz] = Util::$Z;
            }
        }
        return $output;
    }

    /**
     * Return seconds based on an offset, [+/-]HHmm[ss], used when correcting UTC to localtime or v.v.
     *
     * @param string $tz
     * @return integer
     * @static
     * @author Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>
     * @since  2.26.7 - 2018-11-23
     */
    public static function tz2offset( $tz ) {
        $tz     = trim( (string) $tz );
        $offset = 0;
        $strlen = strlen( $tz );
        if( ( 5 > $strlen ) || ( 9 < $strlen ) ) {
            return $offset;
        }
        if( ! in_array( $tz[0], Util::$PLUSMINUSARR ) ) {
            return $offset;
        }
        $isMinus = ( Util::$MINUS == $tz[0] );
        if( ! ctype_digit( substr( $tz, 1 ))) {
            return $offset;
        }
        if( 6 == $strlen ) {
            if( Util::$COLON != substr( $tz, 3, 1 )) {
                return $offset;
            }
            $tz = substr( $tz, 0, 3 ) . substr( $tz, 4 );
        }
        elseif( 9 == $strlen ) {
            if( ( Util::$COLON != substr( $tz, 3, 1 )) ||
                ( Util::$COLON != substr( $tz, 6, 1 )) ) {
                return $offset;
            }
            $tz = substr( $tz, 0, 3 ) . substr( $tz, 4, 2 ) . substr( $tz, 5 );
        }
        $hours2sec = (int) substr( $tz, 1, 2 ) * 3600;
        $min2sec   = (int) substr( $tz, 3, 2 ) * 60;
        $sec       = ( 6 >= $strlen ) ? 0 : (int) substr( $tz, 5 );
        $offset    = $hours2sec + $min2sec + $sec;
        $offset    = $isMinus ? $offset * -1 : $offset;
        return $offset;
    }
}