(PHP 5 >= 5.2.1, PHP 7)
DateTime::getOffset -- DateTimeImmutable::getOffset -- DateTimeInterface::getOffset -- date_offset_get — Returns the timezone offset
面向对象风格
过程化风格
Returns the timezone offset.
object仅为过程化风格：由 date_create() 返回的 DateTime 类型的对象。
Returns the timezone offset in seconds from UTC on success
或者在失败时返回 FALSE.
Example #1 DateTime::getOffset() example
面向对象风格
<?php
$winter = new DateTime('2010-12-21', new DateTimeZone('America/New_York'));
$summer = new DateTime('2008-06-21', new DateTimeZone('America/New_York'));
echo $winter->getOffset() . "\n";
echo $summer->getOffset() . "\n";
?>
过程化风格
<?php
$winter = date_create('2010-12-21', timezone_open('America/New_York'));
$summer = date_create('2008-06-21', timezone_open('America/New_York'));
echo date_offset_get($winter) . "\n";
echo date_offset_get($summer) . "\n";
?>
以上例程会输出：
-18000 -14400
Note: -18000 = -5 hours, -14400 = -4 hours.
This will be useful for converting offset values into GMT format
<?php
//target time zone
$target_time_zone = new DateTimeZone('America/Los_Angeles');
//find kolkata time
$kolkata_date_time = new DateTime('now', $target_time_zone);
//get the exact GMT format
echo 'GMT '.$kolkata_date_time->format('P');