DateTime::setTimezone

date_timezone_set

(PHP 5 >= 5.2.0, PHP 7)

DateTime::setTimezone -- date_timezone_set — Sets the time zone for the DateTime object

Description

Object oriented style

public DateTime DateTime::setTimezone ( DateTimeZone $timezone )

Procedural style

DateTime date_timezone_set ( DateTime $object , DateTimeZone $timezone )

Sets a new timezone for a DateTime object.

Parameters

object: Procedural style only: A DateTime object returned by date_create(). The function modifies this object.
timezone: A DateTimeZone object representing the desired time zone.

Return Values

Returns the DateTime object for method chaining or FALSE on failure.

Changelog

Version	Description
5.3.0	Changed the return value on success from `NULL` to DateTime.

Examples

Example #1 DateTime::setTimeZone() example

Object oriented style


<?php
$date = new DateTime('2000-01-01', new DateTimeZone('Pacific/Nauru'));
echo $date->format('Y-m-d H:i:sP') . "\n";

$date->setTimezone(new DateTimeZone('Pacific/Chatham'));
echo $date->format('Y-m-d H:i:sP') . "\n";
?>

Procedural style


<?php
$date = date_create('2000-01-01', timezone_open('Pacific/Nauru'));
echo date_format($date, 'Y-m-d H:i:sP') . "\n";

date_timezone_set($date, timezone_open('Pacific/Chatham'));
echo date_format($date, 'Y-m-d H:i:sP') . "\n";
?>

The above examples will output:

2000-01-01 00:00:00+12:00
2000-01-01 01:45:00+13:45

User Contributed Notes

jamsilver at gmail dot com

10 months ago


In response to the other comments expressing surprise that changing the timezone does not affect the timestamp:

A UNIX timestamp is defined as the number of seconds that have elapsed since 00:00:00 (UTC), Thursday, 1 January 1970.

So: with respect to UTC. Always.

Calling setTimezone() never changes the actual "absolute", underlying, moment-in-time itself. It only changes the timezone you wish to "view" that moment "from". Consider the following:

<?php
// A time in London.
$datetime = new DateTime('2015-06-22T10:40:25', new DateTimeZone('Europe/London'));

// I wonder how that SAME moment-in-time would 
// be described in other places around the world.
$datetime->setTimezone(new DateTimeZone('Australia/Sydney'));
print $datetime->format('Y-m-d H:i:s (e)');
  // 2015-06-22 19:40:25 (Australia/Sydney)

$datetime->setTimezone(new DateTimeZone('America/New_York'));
print $datetime->format('Y-m-d H:i:s (e)');
  // 2015-06-22 05:40:25 (America/New_York)

$datetime->setTimezone(new DateTimeZone('Asia/Calcutta'));
print $datetime->format('Y-m-d H:i:s (e)');
  // 2015-06-22 15:10:25 (Asia/Calcutta)
?>

Please note that ALL of these date strings unambiguously represent the exact same moment-in-time. Therefore, calling getTimestamp() at any stage will return the same result:

<?php
$datetime->getTimestamp();
  // 1434966025
?>

salladin

3 years ago


I found unexpected behaviour when passing a timestamp.
timezone seems to always be GMT+0000 unless setTimezone() is set.

<?php

$MNTTZ = new DateTimeZone('America/Denver');
$ts = 1336476757;

$dt = new DateTime("@$ts", $MNTTZ);
var_dump($dt->format('T'), $dt->format('U'));

$dt->setTimezone($MNTTZ);
var_dump($dt->format('T'), $dt->format('U'));

/** Output:
string(8) "GMT+0000"
string(10) "1336476757"
string(3) "MDT"
string(10) "1336476757"
**/

?>

keithm at aoeex dot com

6 years ago


The timestamp value represented by the DateTime object is not modified when you set the timezone using this method.  Only the timezone, and thus the resulting display formatting, is affected.

This can be seen using the following test code:
<?php
$MNTTZ = new DateTimeZone('America/Denver');
$ESTTZ = new DateTimeZone('America/New_York');

$dt = new DateTime('11/24/2009 2:00 pm', $MNTTZ);
var_dump($dt->format(DATE_RFC822), $dt->format('U'));
$dt->setTimezone($ESTTZ);
var_dump($dt->format(DATE_RFC822), $dt->format('U'));

/** Output:
string(29) "Tue, 24 Nov 09 14:00:00 -0700"
string(10) "1259096400"
string(29) "Tue, 24 Nov 09 16:00:00 -0500"
string(10) "1259096400"
**/
?>

As such, you can use this to easily convert between timezones for display purposes.

balbuf

2 months ago


It appears that what forzi at mail333 dot com said is correct.



When you reset the timezone on a DateTime object using a timezone that was instantiated with a GMT offset (e.g. <?php new DateTimeZone('-0500'); ?>) the timestamp as reported by <?php $dt->format('U'); ?> changes. 



However, the value reported by <?php $dt->getTimestamp(); ?> does _not_ change. Interestingly, once <?php $dt->getTimestamp(); is called, the value from <?php $dt->format('U'); ?> starts returning the correct timestamp. This appears to be a bug.



In any case, other output values from format() seem to be accurate, and the true timestamp is always accessible via getTimestamp().

forzi at mail333 dot com

1 year ago


<?php
$MNTTZ = new DateTimeZone('America/Denver');
$ESTTZ = new DateTimeZone('America/New_York');

$dt = new DateTime('11/24/2009 2:00 pm', $MNTTZ);
var_dump($dt->format(DATE_RFC822), $dt->format('U'));
$dt->setTimezone($ESTTZ);
var_dump($dt->format(DATE_RFC822), $dt->format('U'));
?>
doesn't changes timestamp
But
<?php
$MNTTZ = new DateTimeZone('America/Denver');
$ESTTZ = new DateTimeZone('-0500');

$dt = new DateTime('11/24/2009 2:00 pm', $MNTTZ);
var_dump($dt->format(DATE_RFC822), $dt->format('U'));
$dt->setTimezone($ESTTZ);
var_dump($dt->format(DATE_RFC822), $dt->format('U'));
?>
changes timestamp

It is possible to fix that by:
<?php
$timestamp = $date->getTimestamp();
$date->setTimezone($value);
$date->setTimestamp($timestamp);
?>
But WTF???