(PHP 5 >= 5.5.0, PHP 7, PHP 8, PECL >= 3.0.0a1)
IntlCalendar::inDaylightTime — Whether the objectʼs time is in Daylight Savings Time
Object-oriented style
Procedural style
Whether, for the instant represented by this object and for this objectʼs timezone, daylight saving time is in place.
calendarAn IntlCalendar instance.
Returns true if the date is in Daylight Savings Time, false otherwise.
On failure false is also returned. To detect error conditions use intl_get_error_code(), or set up Intl to throw exceptions.
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