timezone_location_get
Another way to do this is to wrap the function in a class that extends the DateTimeZone class:
<?php
/**
* Helps with timezones.
* @link http://us.php.net/manual/en/class.datetimezone.php
*
* @package Date
*/
class Helper_DateTimeZone extends DateTimeZone
{
/**
* Converts a timezone hourly offset to its timezone's name.
* @example $offset = -5, $isDst = 0 <=> return value = 'America/New_York'
*
* @param float $offset The timezone's offset in hours.
* Lowest value: -12 (Pacific/Kwajalein)
* Highest value: 14 (Pacific/Kiritimati)
* @param bool $isDst Is the offset for the timezone when it's in daylight
* savings time?
*
* @return string The name of the timezone: 'Asia/Tokyo', 'Europe/Paris', ...
*/
final public static function tzOffsetToName($offset, $isDst = null)
{
if ($isDst === null)
{
$isDst = date('I');
}
$offset *= 3600;
$zone = timezone_name_from_abbr('', $offset, $isDst);
if ($zone === false)
{
foreach (timezone_abbreviations_list() as $abbr)
{
foreach ($abbr as $city)
{
if ((bool)$city['dst'] === (bool)$isDst &&
strlen($city['timezone_id']) > 0 &&
$city['offset'] == $offset)
{
$zone = $city['timezone_id'];
break;
}
}
if ($zone !== false)
{
break;
}
}
}
return $zone;
}
}
?>
Then you could do something like this:
<?php
$Dtz = new Helper_DateTimeZone(Helper_DateTimeZone::tzOffsetToName(-5));
var_dump($Dtz->getName());
string(16) "America/New_York"
?>
timezone_name_from_abbr
(PHP 5 >= 5.1.3)
timezone_name_from_abbr — Returns the timezone name from abbreviation
Description
string timezone_name_from_abbr
( string $abbr
[, int $gmtOffset = -1
[, int $isdst = -1
]] )
Parameters
- abbr
-
Time zone abbreviation.
- gmtOffset
-
Offset from GMT in seconds. Defaults to -1 which means that first found time zone corresponding to abbr is returned. Otherwise exact offset is searched and only if not found then the first time zone with any offset is returned.
- isdst
-
Daylight saving time indicator. If abbr doesn't exist then the time zone is searched solely by offset and isdst .
Return Values
Returns time zone name on success or FALSE on failure.
Examples
Example #1 A timezone_name_from_abbr() example
<?php
echo timezone_name_from_abbr("CET") . "\n";
echo timezone_name_from_abbr("", 3600, 0) . "\n";
?>
The above example will output something similar to:
Europe/Berlin Europe/Paris
add a note
User Contributed Notestimezone_name_from_abbr
Master Tablu
24-Feb-2009 03:03
24-Feb-2009 03:03
chris at mretc dot net
11-Nov-2008 01:25
11-Nov-2008 01:25
timezone_name_from_abbr() sometimes returns FALSE instead of an actual timezone: http://bugs.php.net/44780
It's possible to workaround it for some cases by getting the timezone name from timezone_abbreviations_list(). For example, if you have the GMT offset and want a timezone name:
<?php
/* Takes a GMT offset (in hours) and returns a timezone name */
function tz_offset_to_name($offset)
{
$offset *= 3600; // convert hour offset to seconds
$abbrarray = timezone_abbreviations_list();
foreach ($abbrarray as $abbr)
{
foreach ($abbr as $city)
{
if ($city['offset'] == $offset)
{
return $city['timezone_id'];
}
}
}
return FALSE;
}
?>