date_default_timezone_get()
(PHP 5 >= 5.1.0, PHP 7)
取得一个脚本中所有日期时间函数所使用的默认时区
说明
date_default_timezone_get(void): string
本函数返回默认时区,使用如下“假定”的顺序:
用date_default_timezone_set()函数设定的时区(如果设定了的话)
仅仅在 PHP 5.4.0 之前:TZ环境变量(如果非空)
date.timezone配置选项(如果设定了的话)
仅仅在 PHP 5.4.0 之前:查询操作系统主机(如果操作系统支持并允许)。 This uses an algorithm that has toguessthe timezone. This is by no means going to work correctly for every situation. A warning is shown when this stage is reached. Do not rely on it to be guessed correctly, and setdate.timezoneto the correct timezone instead.
如果以上选择都不成功,date_default_timezone_get()会则返回UTC的默认时区。
返回值
返回一个string。
更新日志
版本 | 说明 |
---|---|
5.4.0 | 不再使用TZ来推测时区。 |
5.4.0 | 不再根据操作系统的信息来推测时区,因为这是不可靠的。 |
范例
获取默认时区
<?php date_default_timezone_set('Europe/London'); if (date_default_timezone_get()) { echo 'date_default_timezone_set: ' . date_default_timezone_get() . '<br />'; } if (ini_get('date.timezone')) { echo 'date.timezone: ' . ini_get('date.timezone'); } ?>
以上例程的输出类似于:
date_default_timezone_set: Europe/London date.timezone: Europe/London
获取一个时区的简写
<?php date_default_timezone_set('America/Los_Angeles'); echo date_default_timezone_get() . ' => ' . date('e') . ' => ' . date('T'); ?>
以上例程会输出:
America/Los_Angeles => America/Los_Angeles => PST
参见
date_default_timezone_set()
设定用于一个脚本中所有日期时间函数的默认时区- 所支持的时区列表
Please note that on Debian/Ubuntu this function will return the system timezone defined in /etc/localtime if date.timezone is not defined, even with PHP 5.4+ See http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=673763#10
In my case, I'm not sure I can guess the correct timezone any better than PHP and it's no where near important enough to nag the user, so... <?php // Suppress DateTime warnings date_default_timezone_set(@date_default_timezone_get()); ?>
Please note that "Damien dot Garrido dot Work at gmail dot com" code is wrong, the third parameter of sprintf must be divided by 60. This is the corrected function: <?php function timezone_offset_string( $offset ) { return sprintf( "%s%02d:%02d", ( $offset >= 0 ) ? '+' : '-', abs( $offset / 3600 ), abs( $offset % 3600 ) / 60 ); } ?>
To get offset string from offset: <?php function timezone_offset_string( $offset ) { return sprintf( "%s%02d:%02d", ( $offset >= 0 ) ? '+' : '-', abs( $offset / 3600 ), abs( $offset % 3600 ) ); } $offset = timezone_offset_get( new DateTimeZone( 'Pacific/Kiritimati' ), new DateTime() ); echo "offset: " . timezone_offset_string( $offset ) . "\n"; $offset = timezone_offset_get( new DateTimeZone( 'Pacific/Tahiti' ), new DateTime() ); echo "offset: " . timezone_offset_string( $offset ) . "\n"; ?> Output: offset: +14:00 offset: -10:00
For the reason that date_default_timezone_get() throws an error when the timezone isn't set in php.ini and then returns a default chosen by the system (rather than returning false to indicate to the script that a timezone hasn't been set), I've found that the following works when you want a script to detect when the ini value has not been set and want the script itself to choose a default in that case, while still allowing bootstrap scripts to set their own default using date_default_timezone_set(). <?php set_error_handler(function ($errno, $errstr){ throw new Exception($errstr); return false; }); try{ date_default_timezone_get(); } catch(Exception $e){ date_default_timezone_set('UTC'); // Sets to UTC if not specified anywhere in .ini } restore_error_handler();
If you want to get the abbrivation (3 or 4 letter), instead of the long timezone string you can use date('T') function like this: Input: date_default_timezone_set('America/Los_Angeles'); echo date_default_timezone_get(); echo ' => '.date('e'); echo ' => '.date('T'); Output: America/Los_Angeles => America/Los_Angeles => PST
date_default_timezone_get() will still emit a warning in E_STRICT if the timezone is not set; either by date_default_timezone_set() or the ini option of date.timezone. This is probably not a big deal, but I thought I would contribute what I found.