(PHP 5 >= 5.5.0, PHP 7, PHP 8, PECL >= 3.0.0a1)
IntlCalendar::inDaylightTime — Whether the object?s time is in Daylight Savings Time
面向对象风格
过程化风格
Whether, for the instant represented by this object and for this object?s timezone, daylight saving time is in place.
calThe IntlCalendar resource.
Returns true if the date is in Daylight Savings Time, false otherwise.
The value false may also be returned on failure, for instance after
specifying invalid field values on non-lenient mode; use exceptions or query
intl_get_error_code() to disambiguate.
Example #1 IntlCalendar::inDaylightTime()
<?php
ini_set('date.timezone', 'Europe/Lisbon');
ini_set('intl.default_locale', 'pt_PT');
$cal = new IntlGregorianCalendar(2013, 6 /* July */, 1, 4, 56, 31);
var_dump($cal->inDaylightTime()); // true
$cal->set(IntlCalendar::FIELD_MONTH, 11 /* December */);
var_dump($cal->inDaylightTime()); // false
//DST end transition on 2013-10-27 at 0200 (wall time back 1 hour)
$cal = new IntlGregorianCalendar(2013, 9 /* October */, 27, 1, 30, 0);
var_dump($cal->inDaylightTime()); // false (default WALLTIME_LAST)
$cal->setRepeatedWallTimeOption(IntlCalendar::WALLTIME_FIRST);
$cal->set(IntlCalendar::FIELD_HOUR_OF_DAY, 1); // force time recalculation
var_dump($cal->inDaylightTime()); // true