timezone_name_from_abbr - PHP code example

PHP Function Timezone_Name_From_Abbr

Working with timezones can be a challenging aspect of web applications. Advanced techniques, like converting dates and times between timezones, handling DST transitions, and using timezone databases, can help developers build robust and accurate applications that work well for users across the globe. In this article, we'll review the php function timezone_name_from_abbr, which allows developers to turn abbreviated time zone names, such as EST and PST, into full time zone names, such as America/New_York and America/Los_Angeles.

timezone_name_from_abbr() is an inbuilt function in PHP that returns the name of the time zone from an abbreviation passed as its parameter. This function takes three parameters – abbreviation, gmtoffset and isdst. Abbreviation is the mandatory parameter, if the abbreviation is not found then -1 is returned. gmtoffset is the offset from GMT in seconds and isdst is an optional flag that indicates whether or not daylight saving is in effect.

The php function is simple to use, simply pass the abbreviation of your time zone as its parameter and it will return the corresponding full timezone name. This function works with any timezone database, like Olson, and supports a wide range of abbreviations, such as EST and PST. You can also pass a string as the parameter, allowing you to specify the exact timezone name that you want to find. This function was introduced in PHP version 5.2.0 and is compatible with all the later versions. The php timezone_name_from_abbr() function returns a string value on success and a boolean value on failure.

timezone_name_from_abbr example

if ($timeZone === 'SYSTEM') {
                $timeZone = $connection->executeQuery('SELECT @@system_time_zone')->fetchOne();
            }
        } catch (PDOException $e) {
        }

        if (!empty($timeZone)) {
            $databaseZone = null;
            if (\in_array($timeZone[0], ['-', '+'], true)) {
                $databaseZone = new DateTimeZone($timeZone);
            } else {
                $timeZoneFromAbbr = timezone_name_from_abbr($timeZone);
                if (\is_string($timeZoneFromAbbr)) {
                    $databaseZone = timezone_open($timeZoneFromAbbr);
                    if (!$databaseZone instanceof DateTimeZone) {
                        $databaseZone = null;
                    }
                }
            }

            $phpZone = timezone_open(date_default_timezone_get());
            if ($databaseZone instanceof DateTimeZone && $phpZone instanceof DateTimeZone) {
                $databaseTime = new DateTime('now', $databaseZone);

$original = intval($is_daylight_saving_time);
      $is_daylight_saving_time = min(1, max(-1, intval($is_daylight_saving_time)));
      // Catch if out of boundary.       if ($original !== $is_daylight_saving_time) {
        return new JsonResponse(FALSE);
      }
    }

    // An abbreviation of "0" passed in the callback arguments should be     // interpreted as the empty string.     $abbreviation = $abbreviation ? $abbreviation : '';
    $timezone = timezone_name_from_abbr($abbreviation, $offset, $is_daylight_saving_time);
    return new JsonResponse($timezone);
  }

}

class TimeZone extends ProcessPluginBase {

  /** * {@inheritdoc} */
  public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
    $offset = $value;
    // Convert the integer value of the offset (which can be either     // negative or positive) to a timezone name.     // Note: Daylight saving time is not to be used.     $timezone_name = timezone_name_from_abbr('', intval($offset), 0);
    if (!$timezone_name) {
      $timezone_name = 'UTC';
    }

    return $timezone_name;
  }

}