(PHP 5 >= 5.6.0, PHP 7)
DateTimeImmutable::createFromMutable — Returns new DateTimeImmutable object encapsulating the given DateTime object
datetimeThe mutable DateTime object that you want to convert to an immutable version. This object is not modified, but instead a new DateTimeImmutable object is created containing the same date time and timezone information.
Example #1 Creating an immutable date time object
<?php
$date = new DateTime("2014-06-20 11:45 Europe/London");
$immutable = DateTimeImmutable::createFromMutable( $date );
?>
Returns a new DateTimeImmutable instance.
For PHP < 5.6
<?php
$date = new DateTime("now", new DateTimeZone("Europe/Paris"));
echo $date->format(DateTime::ISO8601) . PHP_EOL; // 2016-12-08T10:42:59+0100
$datei = DateTimeImmutable::createFromFormat(DateTime::ISO8601, $date->format(DateTime::ISO8601));
echo $datei->format(DateTime::ISO8601) . PHP_EOL; // 2016-12-08T10:42:59+0100
?>