timezone_offset_get

(PHP 5 >= 5.1.0)

timezone_offset_get — Returns the timezone offset from GMT

Description

int timezone_offset_get ( DateTimeZone $object , DateTime $datetime )

int DateTimeZone::getOffset ( DateTime $datetime )

This function returns the offset to GMT for the date/time specified in the datetime parameter. The GMT offset is calculated with the timezone information contained in the DateTime object being used.

Parameters

object: DateTimeZone object.
datetime: DateTime that contains the date/time to compute the offset from.

Return Values

Returns time zone offset in seconds on success or FALSE on failure.

Examples

Example #1 timezone_offset_get() examples


<?php
// Create two timezone objects, one for Taipei (Taiwan) and one for
// Tokyo (Japan)
$dateTimeZoneTaipei = new DateTimeZone("Asia/Taipei");
$dateTimeZoneJapan = new DateTimeZone("Asia/Tokyo");

// Create two DateTime objects that will contain the same Unix timestamp, but
// have different timezones attached to them.
$dateTimeTaipei = new DateTime("now", $dateTimeZoneTaipei);
$dateTimeJapan = new DateTime("now", $dateTimeZoneJapan);

// Calculate the GMT offset for the date/time contained in the $dateTimeTaipei
// object, but using the timezone rules as defined for Tokyo
// ($dateTimeZoneJapan).
$timeOffset = $dateTimeZoneJapan->getOffset($dateTimeTaipei);

// Should show int(32400) (for dates after Sat Sep 8 01:00:00 1951 JST).
var_dump($timeOffset);
?>

add a note User Contributed Notes
timezone_offset_get

[d][a][n][at][authenticdesign][.][net]
22-May-2008 05:02


Hi,

This might help someone with timezone differences. I wanted to find the offset in seconds between my timezone and a remote timezone so I wrote this function and it seems to work well for me.



<?php

/**    Returns the offset from the origin timezone to the remote timezone, in seconds.

*    @param $remote_tz;

*    @param $origin_tz; If null the servers current timezone is used as the origin.

*    @return int;

*/

function get_timezone_offset($remote_tz, $origin_tz = null) {

    if($origin_tz === null) {

        if(!is_string($origin_tz = date_default_timezone_get())) {

            return false; // A UTC timestamp was returned -- bail out!

        }

    }

    $origin_dtz = new DateTimeZone($origin_tz);

    $remote_dtz = new DateTimeZone($remote_tz);

    $origin_dt = new DateTime("now", $origin_dtz);

    $remote_dt = new DateTime("now", $remote_dtz);

    $offset = $origin_dtz->getOffset($origin_dt) - $remote_dtz->getOffset($remote_dt);

    return $offset;

}

?>

Examples:

<?php

// This will return 10800 (3 hours) ...

$offset = get_timezone_offset('America/Los_Angeles','America/New_York');

// or, if your server time is already set to 'America/New_York'...

$offset = get_timezone_offset('America/Los_Angeles');

// You can then take $offset and adjust your timestamp.

$offset_time = time() + $offset;

?>



Happy Coding!!

richard at phase dot org
20-Mar-2007 06:05


The following extended example may make the usage clearer; 

<?php

// Create two timezone objects, one for Taipei (Taiwan) and one for

// Tokyo (Japan)

$dateTimeZoneTaipei = new DateTimeZone("Asia/Taipei");

$dateTimeZoneJapan = new DateTimeZone("Asia/Tokyo");



// Create two DateTime objects that will contain the same Unix timestamp, but

// have different timezones attached to them.

$dateTimeTaipei = new DateTime("now", $dateTimeZoneTaipei);

$dateTimeJapan = new DateTime("now", $dateTimeZoneJapan);



// NOTE: $dateTimeJapan is not used further in this example



// Calculate the GMT offset for the date/time contained in the $dateTimeTaipei

// object, but using the timezone rules as defined for Tokyo

// ($dateTimeZoneJapan).

$timeOffset = $dateTimeZoneJapan->getOffset($dateTimeTaipei);



// Should show int(32400) (for dates after Sat Sep 8 01:00:00 1951 JST).

print("Number of seconds Japan is ahead of GMT at the specific time: ");

var_dump($timeOffset);



print("<br />Number of seconds Taipei is ahead of GMT at the specific time: ");

var_dump($dateTimeZoneTaipei->getOffset($dateTimeTaipei));



print("<br />Number of seconds Japan is ahead of Taipei at the specific time: ");

var_dump($dateTimeZoneJapan->getOffset($dateTimeTaipei)

     -$dateTimeZoneTaipei->getOffset($dateTimeTaipei));



print("<hr />");



?>



Number of seconds Japan is ahead of GMT at the specific time: int(32400)

Number of seconds Taipei is ahead of GMT at the specific time: int(28800)

Number of seconds Japan is ahead of Taipei at the specific time: int(3600)

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Last updated: Fri, 22 Aug 2008