DateTimeZone::listAbbreviations

timezone_abbreviations_list

(PHP 5 >= 5.2.0, PHP 7, PHP 8)

DateTimeZone::listAbbreviations -- timezone_abbreviations_list — 返回一个包含 dst (夏令时)，时差和时区信息的关联数组。

说明

面向对象风格

public static DateTimeZone::listAbbreviations ( ) : array

过程化风格

timezone_abbreviations_list ( ) : array

返回值

成功，返回数组，或者在失败时返回 false。

范例

Example #1 timezone_abbreviations_list() 函数的范例：


<?php
$timezone_abbreviations = DateTimeZone::listAbbreviations();
print_r($timezone_abbreviations["acst"]);
?>

以上例程的输出类似于：

Array
(
    [0] => Array
        (
            [dst] => 1
            [offset] => -14400
            [timezone_id] => America/Porto_Acre
        )

    [1] => Array
        (
            [dst] => 1
            [offset] => -14400
            [timezone_id] => America/Eirunepe
        )

    [2] => Array
        (
            [dst] => 1
            [offset] => -14400
            [timezone_id] => America/Rio_Branco
        )

    [3] => Array
        (
            [dst] => 1
            [offset] => -14400
            [timezone_id] => Brazil/Acre
        )

)

参见

timezone_identifiers_list() - 别名 DateTimeZone::listIdentifiers

User Contributed Notes

jonathan at hogervorst dot info 17-Jan-2014 11:32


This method returns an associative array containing some 'major' timezones (like CEST), which on their own contain more specific 'geographic' timezones (like Europe/Amsterdam).



If you're using these timezones and their offset/DST information, it's extremely important to realize the following:



*It seems like ALL DIFFERENT OFFSET/DST CONFIGURATIONS (including historical configurations) of each timezone are included!*



For example, Europe/Amsterdam can be found six times in the output of this function. Two occurrences (offset 1172/4772) are for the Amsterdam time used until 1937; two (1200/4800) are for the time that was used between 1937 and 1940; and two (3600/4800) are for the time used since 1940.



*Therefore, YOU CANNOT RELY ON THE OFFSET/DST INFORMATION RETURNED BY THIS FUNCTION as being currently correct/in use!*



If you want to know the current offset/DST of a certain timezone, you'll have to do something like this:



<?php

$now = new DateTime(null, new DateTimeZone('Europe/Amsterdam'));

echo $now->getOffset();

?>



P.S. I'm sorry for my use of caps lock in this post, but as this behavior is not described in the documentation, I considered it to be important enough to shout. Normally I don't do such things :)

kingskippus at gmail dot com 04-Apr-2009 08:32


Note that the dst field is of boolean type, so if you are doing an identity comparison, you need to test for true or false, not 0 or 1.  For example:



<?php

  $timezone_abbreviations = DateTimeZone::listAbbreviations();

  foreach ($timezone_abbreviations["est"] as $tz) {

    echo $tz['timezone_id'];

    // if ($tz['dst'] === 1) will always evaluate to false

    if ($tz['dst'] === true) {

      echo " (DST observed)<br />\n";

    }

    // Could use else here, but for illustration...

    if ($tz['dst'] === false) {

      echo " (DST not observed)<br />\n";

    }

  }

?>