IntlTimeZone クラス

Currently there is no documentation available for IntlTimeZone::parse(), so it took some while to figure out a working example:<?php// Example for 32-bit PHP 7.0.30 with Intl version 1.1, ICU version 56.1// To get the offset of a date including daylight saving time, getRawOffset() is// not sufficient, getOffset() is needed. And a date is needed to take history// in to account.\Locale::setDefault('nl-NL');$date = '25-03-2018 12:34:56.123456 CEST';  // 3rd of Februari$timezone = \IntlTimeZone::createDefault();  // = CEST = GMT +02:00print 'Time zone: ' . $timezone->getDisplayName() . PHP_EOL;print 'DST: ' . ($timezone->useDaylightTime() ? 'DOES' : 'DOES NOT')  . ' happen to this timezone' . PHP_EOL;print 'Possible DST difference (usec): ' . $timezone->getDSTSavings() . PHP_EOL;$formatter = new \IntlDateFormatter(  \Locale::getDefault(),  \IntlDateFormatter::MEDIUM,  \IntlDateFormatter::MEDIUM,  $timezone);$timestamp = $formatter->parse($date);if (FALSE === $timestamp) {  throw new \Exception('Can not parse date');}elseif (is_float($timestamp)) {  throw new \Exception('Y2K38 bug @ 32 bit, please use 64 bit');}print 'Date parsed by IntlFormatter::parse(): ' . date('c', $timestamp)  . PHP_EOL;$cal = \IntlCalendar::createInstance();$cal->setTimeZone($timezone);$cal->setLenient(FALSE);// set UNIX timestamp offset (1970-01-01 00:00:00.000000) and add the timestamp$cal->set(1970, 0, 1, 0, 0, 0);$cal->set(\IntlCalendar::FIELD_MILLISECOND, 0); // note: msec, not usec$cal->add(\IntlCalendar::FIELD_SECOND, $timestamp); // note: no milliseconds$cal->add(\IntlCalendar::FIELD_MILLISECOND, 124);  // hardcode for simplicityheader('Content-type: text/plain');print 'Date constructed with IntlCalendar: ' . $formatter->format($cal)  . PHP_EOL;print 'Raw offset by getRawOffset(): ' . $timezone->getRawOffset() . PHP_EOL;/** * Function IntlTimeZone::getOffset() * @link http://icu-project.org/apiref/icu4c/classicu_1_1TimeZone.html#afcbc1c48bf0b453b0123c4cb75d20e96 * @param float $date *   moment in time for which to return offsets, in units of milliseconds from *   January 1, 1970 0:00 GMT, either GMT time or local wall time, depending on *   `local'. * @param bool $local *   if true, `date' is local wall time; otherwise it is in GMT time. * @param int &$rawOffset *   output parameter to receive the raw offset, that is, the offset not *   including DST adjustments * @param int &$dstOffset *   output parameter to receive the DST offset, that is, the offset to be added *   to `rawOffset' to obtain the total offset between local and GMT time. If *   DST is not in effect, this value is zero; otherwise it is a positive value, *   typically one hour. */$rawOffset = NULL;$dstOffset = NULL;$timestamp *= 1000.0; // convert unix timestamp from secs to msecs$timezone->getOffset($timestamp, $local = FALSE, $rawOffset, $dstOffset);print 'Output of getOffset():' . PHP_EOL . json_encode([  'rawOffset' => $rawOffset,  'dstOffset' => $dstOffset], JSON_PRETTY_PRINT) . PHP_EOL;?>