DateTimeZone::getTransitions

timezone_transitions_get

(PHP 5 >= 5.2.0, PHP 7)

DateTimeZone::getTransitions -- timezone_transitions_get — Returns all transitions for the timezone

Description

Object oriented style

public array DateTimeZone::getTransitions ([ int $timestamp_begin [, int $timestamp_end ]] )

Procedural style

array timezone_transitions_get ( DateTimeZone $object [, int $timestamp_begin [, int $timestamp_end ]] )

Parameters

object: Procedural style only: A DateTimeZone object returned by timezone_open()
timestamp_begin: Begin timestamp.
timestamp_end: End timestamp.

Return Values

Returns numerically indexed array containing associative array with all transitions on success or FALSE on failure.

Changelog

Version	Description
5.3.0	The optional `timestamp_begin` and `timestamp_end` were added.

Examples

Example #1 A timezone_transitions_get() example


<?php
$timezone = new DateTimeZone("Europe/London");
$transitions = $timezone->getTransitions();
print_r(array_slice($transitions, 0, 3));
?>

The above example will output something similar to:

Array
(
    [0] => Array
        (
            [ts] => -9223372036854775808
            [time] => -292277022657-01-27T08:29:52+0000
            [offset] => 3600
            [isdst] => 1
            [abbr] => BST
        )

    [1] => Array
        (
            [ts] => -1691964000
            [time] => 1916-05-21T02:00:00+0000
            [offset] => 3600
            [isdst] => 1
            [abbr] => BST
        )

    [2] => Array
        (
            [ts] => -1680472800
            [time] => 1916-10-01T02:00:00+0000
            [offset] => 0
            [isdst] => 
            [abbr] => GMT
        )

)

User Contributed Notes

scotts

6 years ago


Getting a timezone's offset and other data at a specified point in time (now, for example) using the new PHP5.3 parameters:



<?php

$theTime = time(); # specific date/time we're checking, in epoch seconds.



$tz = new DateTimeZone('America/Los_Angeles');

$transition = $tz->getTransitions($theTime,$theTime);



# only one array should be returned into $transition. Now get the data:

$offset = $transition[0]['offset'];

$abbr = $transition[0]['abbr'];

?>



Before PHP5.3, you'd have to loop through all of the Transitions up until the current point in time, which would be a very inefficient process.

rubo77

2 years ago


This will work  in PHP_VERSION < 5.3:

<?php
/** returns an array with two elements for spring and fall DST in a given year
 *  works in PHP_VERSION < 5.3
 * 
 * @param integer $year
 * @param string $tz timezone
 * @return array
 **/
function getTransitionsForYear($year=null, $tz = null){
    if(!$year) $year=date("Y");

    if (!$tz) $tz = date_default_timezone_get();
    $timeZone = new DateTimeZone($tz);

    if (version_compare(PHP_VERSION, '5.3.0') >= 0) {
        $transitions = $timeZone->getTransitions(mktime(0, 0, 0, 2, 1, $year),mktime(0, 0, 0, 11, 31, $year));
        $index=1;
    } else {
        // since 1980 it is regular, the 29th element is 1980-04-06
            // change this in your timezone
            $first_regular_index=29;
            $first_regular_year=1980;
        $transitions = $timeZone->getTransitions();
        $index=($year-$first_regular_year)*2+$first_regular_index;
    }
    return array_slice($transitions, $index, 2);
}

tanguy dot pruvot at gmail dot com

2 years ago


Beware if you use getTransitions() without a minimum date, it can be slow...

rubo77

2 years ago


This function will work in PHP < 5.3 :

/** returns an array with two elements for spring and fall DST in a given year
 *
 * @param integer $year
 * @param string $tz timezone
 * @return array
 **/
function getTransitionsForYear($year=null, $tz = null){
    if(!$year) $year=date("Y");
    
    if (!$tz) $tz = date_default_timezone_get();
    $timeZone = new DateTimeZone($tz);
    
    $transitions = $timeZone->getTransitions(mktime(0, 0, 0, 1, 1, $year));
    return array_slice($transitions, 1, 2);
}