Returns an array of all timezones PHP recognizes. Inspired by code from: https://stackoverflow.com/questions/1727077/generating-a-drop-down-list-...

This code will return the common US timezones first, followed by the rest of the timezones that PHP is aware of.

File

includes/misc.inc, line 425

This file contains misc functions for FlightPath

Code

function get_timezones($bool_include_offset = FALSE) {

  $timezones = array();

  // These are the common names for the US timezones.  
  $us_desc_timezones = array(
    'America/New_York' => 'Eastern',
    'America/Chicago' => 'Central',
    'America/Denver' => 'Mountain',
    'America/Phoenix' => 'Mountain no DST',
    'America/Los_Angeles' => 'Pacific',
    'America/Anchorage' => 'Alaska',
    'America/Adak' => 'Hawaii',
    'Pacific/Honolulu' => 'Hawaii no DST',
  );


  $us_timezones = array_keys($us_desc_timezones);


  $timezones = DateTimeZone::listIdentifiers(DateTimeZone::ALL);

  // Place the US timezones at the top of the list.
  $timezones = array_merge($us_timezones, $timezones);


  $timezone_offsets = array();
  foreach ($timezones as $timezone) 
   {
    $tz = new DateTimeZone($timezone);
    $timezone_offsets [$timezone] = $tz->getOffset(new DateTime);
  }


  $timezone_list = array();
  foreach ($timezone_offsets as $timezone => $offset) 
   {
    $offset_prefix = $offset < 0 ? '-' : '+';
    $offset_formatted = gmdate('H:i', abs($offset));

    $pretty_offset = $extra = "";
    if ($bool_include_offset) {
      $pretty_offset = "(UTC${offset_prefix}${offset_formatted}) ";
    }

    if (isset($us_desc_timezones [$timezone])) {
      $extra = "  - (" . $us_desc_timezones [$timezone] . ")";
    }

    $disp_timezone = str_replace("_", " ", $timezone);
    $timezone_list [$timezone] = "$pretty_offset$disp_timezone$extra";
  }

  return $timezone_list;
}