PHP 7.0.6 Released

    timezone_name_from_abbr

    (PHP 5 >= 5.1.3, PHP 7)

    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. Defaults to -1, which means that whether the time zone has daylight saving or not is not taken into consideration when searching. If this is set to 1, then the gmtOffset is assumed to be an offset with daylight saving in effect; if 0, then gmtOffset is assumed to be an offset without daylight saving in effect. If abbr doesn't exist then the time zone is searched solely by the gmtOffset 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

    See Also

    User Contributed Notes

    chris at mretc dot net
    7 years ago
    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;
    }
    ?>
    Master Tablu
    7 years ago
    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"
    ?>
    atrauzzi at gmail dot com
    1 month ago
    Fun fact: (60*60) * -2 always seems to return null.

    Perhaps because there's no timezone that corresponds to UTC -2.
    To Top