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<IntlCalendar::getWeekendTransitionIntlCalendar::isEquivalentTo>
^IntlCalendarLast updated: Mon, 26 Oct 2026

IntlCalendar::inDaylightTime

(PHP 5 >= 5.5.0, PHP 7, PHP 8, PECL >= 3.0.0a1)

IntlCalendar::inDaylightTime — Whether the objectʼs time is in Daylight Savings Time

Description

Object-oriented style

public function IntlCalendar::inDaylightTime(): bool

Procedural style

function intlcal_in_daylight_time(IntlCalendar $calendar): bool

Whether, for the instant represented by this object and for this objectʼs timezone, daylight saving time is in place.

Parameters

calendar

An IntlCalendar instance.

Return Values

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.

Examples

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


<IntlCalendar::getWeekendTransitionIntlCalendar::isEquivalentTo>
^IntlCalendarLast updated: Mon, 26 Oct 2026