DateTimeImmutable::createFromTimestamp() uses UTC timezone

[MircoBabin]

Affected page

https://www.php.net/manual/en/datetimeimmutable.createfromtimestamp.php

Current issue

It is not documented that createFromTimestamp() sets the timezone to UTC. Which is unexpected, because the absence of a timezone normally uses date_default_timezone_get().

Suggested improvement

1. Document the unexpected UTC timezone.

2. Document the (very ugly) workaround

DateTimeImmutable::createFromTimestamp($someTimestamp)->setTimezone(new DateTimeZone(date_default_timezone_get()));

Additional context (optional)

I created a test at https://3v4l.org/d3Rq1#v8.5.7 which demonstrates the current behaviour.

<?php

if (!date_default_timezone_set('Europe/Amsterdam')) {
    throw new Exception('Timezone Europe/Amsterdam does not exist?');
}

echo 'Default timezone: '.date_default_timezone_get().PHP_EOL;
var_dump(new DateTimeZone(date_default_timezone_get()));

$someTimestamp = strtotime('2026-07-03 14:22:17');

echo '--- date'.PHP_EOL;
echo date('Y-m-d H:i:s', $someTimestamp).PHP_EOL;

echo '--- DateTimeImmutable::createFromTimestamp() defaults to UTC timezone'.PHP_EOL;
$dt = DateTimeImmutable::createFromTimestamp($someTimestamp);
echo $dt->format('Y-m-d H:i:s').PHP_EOL;
var_dump($dt->getTimezone());

echo '--- DateTimeImmutable::createFromTimestamp() workaround for current timezone'.PHP_EOL;
$dt = DateTimeImmutable::createFromTimestamp($someTimestamp)->setTimezone(new DateTimeZone(date_default_timezone_get()));
echo $dt->format('Y-m-d H:i:s').PHP_EOL;
var_dump($dt->getTimezone());

outputs:

Default timezone: Europe/Amsterdam
object(DateTimeZone)#1 (2) {
  ["timezone_type"]=>
  int(3)
  ["timezone"]=>
  string(16) "Europe/Amsterdam"
}
--- date
2026-07-03 14:22:17
--- DateTimeImmutable::createFromTimestamp() defaults to UTC timezone
2026-07-03 12:22:17                          !!!!!!!! NOTICE THE 2 HOURS DIFFERENCE  !!!!!!!!
object(DateTimeZone)#2 (2) {
  ["timezone_type"]=>
  int(1)
  ["timezone"]=>
  string(6) "+00:00"
}
--- DateTimeImmutable::createFromTimestamp() workaround for current timezone
2026-07-03 14:22:17
object(DateTimeZone)#1 (2) {
  ["timezone_type"]=>
  int(3)
  ["timezone"]=>
  string(16) "Europe/Amsterdam"
}

[kamil-tekiela]

There is no time zone parameter in createFromTimestamp(). Unix timestamps carry timezone information because they are by definition the number of seconds elapsed since Unix epoch. I believe it was a conscious decision not to allow the time zone as a parameter to this method. In __construct() the last parameter is the time zone. If you do not specify it, then it will default to the time zone from date_default_timezone_get(). Same with createFromFormat(). However, even if you use the constructor or createFromFormat() with a Unix timestamp, it will still use the UTC time zone because a timestamp implies that it's UTC.

<?php

if (!date_default_timezone_set('Europe/Amsterdam')) {
    throw new Exception('Timezone Europe/Amsterdam does not exist?');
}

$someTimestamp = strtotime('2026-07-03 14:22:17');

$dt = DateTimeImmutable::createFromTimestamp($someTimestamp);
// is the same as:
$dt = new DateTime('@'.$someTimestamp);

echo $dt->format('Y-m-d H:i:sP');

https://www.php.net/manual/en/datetimeimmutable.construct.php:

Note: The timezone parameter and the current timezone are ignored when the datetime parameter either is a UNIX timestamp (e.g. @946684800) or specifies a timezone (e.g. 2010-01-28T15:00:00+02:00, or 2010-07-05T06:00:00Z).

You are comparing the behaviour to the old date() function which doesn't work the same way. You cannot specify the time zone when using date() function. While it always creates the date from a Unix timestamp, to overcome this limitation the global time zone setting exists and applies in every situation.

What I am trying to say is that createFromTimestamp not applying the time zone is actually the more obvious behaviour. The fact that date() applies the time zone is the more confusing one.

I don't think we need to change anything in the documentation as of now, however, I do see that date() doesn't clearly state that the global time zone is applied.