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.
DateTimeZone::getTransitions
timezone_transitions_get
(PHP 5 >= 5.2.0, PHP 7, PHP 8)
DateTimeZone::getTransitions -- timezone_transitions_get — タイムゾーンの変遷を返す
説明
オブジェクト指向型
public DateTimeZone::getTransitions(int
$timestampBegin = PHP_INT_MIN, int $timestampEnd = PHP_INT_MAX): array|false手続き型
timezone_transitions_get(DateTimeZone
$object, int $timestampBegin = PHP_INT_MIN, int $timestampEnd = PHP_INT_MAX): array|falseパラメータ
-
object -
手続き型のみ: timezone_open() が返す DateTimeZone オブジェクト
-
timestampBegin -
開始時のタイムスタンプ。
-
timestampEnd -
終了時のタイムスタンプ。
戻り値
成功した場合にタイムゾーンの遷移を表す、数値インデックスの配列を返します。
失敗した場合に false を返します。
DateTimeZone オブジェクト の type 1 (UTC オフセット)
と、type 2 (タイムゾーンの省略形) の場合は、
タイムゾーンの遷移情報は含まれません。
その場合にこのメソッドをコールしても false を返します。
timestampBegin を指定すると、
返される配列の最初のエントリに
timestampBegin の時点における遷移の情報が含まれるようになります。
| キー | 型 | 説明 |
|---|---|---|
ts |
int | Unixタイムスタンプ |
time |
string | DateTimeInterface::ISO8601_EXPANDED (PHP
8.2 以降) または、DateTimeInterface::ISO8601 (PHP 8.1 以前) 形式の文字列 |
offset |
int | UTC からのオフセット(秒単位) |
isdst |
bool | 夏時間が有効かどうか |
abbr |
string | タイムゾーンの省略形 |
例
例1 timezone_transitions_get() の例
<?php
$timezone = new DateTimeZone("Europe/London");
$transitions = $timezone->getTransitions();
print_r(array_slice($transitions, 0, 3));
?>上の例の出力は、 たとえば以下のようになります。
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
)
)
例2 timestampBegin を設定して timezone_transitions_get() を使う例
<?php
$timezone = new DateTimeZone("Europe/London");
$transitions = $timezone->getTransitions(time());
print_r(array_slice($transitions, 0, 3));
?>上の例の出力は、 たとえば以下のようになります。
Array
(
[0] => Array
(
[ts] => 1654184161
[time] => 2022-06-02T15:36:01+0000
[offset] => 3600
[isdst] => 1
[abbr] => BST
)
[1] => Array
(
[ts] => 1667091600
[time] => 2022-10-30T01:00:00+0000
[offset] => 0
[isdst] =>
[abbr] => GMT
)
[2] => Array
(
[ts] => 1679792400
[time] => 2023-03-26T01:00:00+0000
[offset] => 3600
[isdst] => 1
[abbr] => BST
)
)
add a note
User Contributed Notes 4 notes
scotts ¶
14 years ago
rubo77 ¶
10 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 ¶
10 years ago
Beware if you use getTransitions() without a minimum date, it can be slow...
rubo77 ¶
10 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);
}
