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
?>
DateTime::setTimezone
date_timezone_set
(PHP 5 >= 5.2.0, PHP 7, PHP 8)
DateTime::setTimezone -- date_timezone_set — Sets the time zone for the DateTime object
Descrizione
Stile orientato agli oggetti
Stile procedurale
Sets a new timezone for a DateTime object.
Like DateTimeImmutable::setTimezone() but works with DateTime.
The procedural version takes the DateTime object as its first argument.
Elenco dei parametri
-
oggetto -
Solo per lo stile procedurale: Un oggetto DateTime restituito da date_create(). La funzione modifica questo oggetto.
-
timezone -
A DateTimeZone object representing the desired time zone.
Valori restituiti
Returns the DateTime object for method chaining. The underlaying point-in-time is not changed when calling this method.
Esempi
Example #1 DateTime::setTimeZone() example
Stile orientato agli oggetti
<?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";
?>Stile procedurale
<?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";
?>I precedenti esempi visualizzeranno:
2000-01-01 00:00:00+12:00 2000-01-01 01:45:00+13:45
Vedere anche:
- DateTimeImmutable::setTimezone() - Sets the time zone
- DateTime::getTimezone() - Return time zone relative to given DateTime
- DateTimeZone::__construct() - Creates new DateTimeZone object
add a note
User Contributed Notes 6 notes
jamsilver at gmail dot com ¶
9 years ago
Alex ¶
8 years ago
Surprising that the timezone works only specified in the separated method in case if you'll use ->format('U').
this does NOT apply timezone +0200 in the $timestamp:
<?php
$date = new \DateTime(strtotime(time()), new DateTimeZone(system('date +%z')));
$timestamp = $date->format('U');
?>
this will apply timezone +0200 in the $timestamp:
<?php
$date = new \DateTime(strtotime(time()));
$date->setTimezone(new DateTimeZone(system('date +%z')));
$timestamp = $date->format('U');
?>
keithm at aoeex dot com ¶
15 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.
forzi at mail333 dot com ¶
10 years 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???
balbuf ¶
8 years 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().
salladin ¶
12 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"
**/
?>
