The DateTimeZone Class in PHP

Specifying timezone to get the date & time of different countries
Get latitude, longitude, and country code for a timezone
Get the timezone offset from UTC (GMT)
Get previous and upcoming Daylight Saving date/time information for a specific timezone
Get time zone information by time zone abbreviations
Get a list of supported timezone identifiers in PHP
1. Get time zone identifiers by region
2. Get timezone identifiers by country

The DateTimeZone class works with the DateTime class. The DateTime constructor takes an optional second argument, which is a DateTimeZone instance. The PHP’s default time zone applies if the second argument is not provided.

Example: Specifying timezone in the constructor

To get the date and time of a specific time zone, pass a valid timezone identifier into the DateTimeZone class constructor:

<?php
 $timezone = new DateTimeZone('Australia/Adelaide');
 $date = new DateTime('now', $timezone);
 echo $date->format('d M Y, H:i:s') . '<br>';
 # 13 Aug 2022, 13:44:31

If you omit the constructor’s second argument, the time zone is determined by PHP’s default timezone setting:

<?php
 // No DateTimeZone instance 
 $date = new DateTime('now');
 echo $date->format('d M Y, H:i:s') . '<br>';
 # 18 Aug 2022, 15:16:29
 
 $timezone = new DateTimeZone('Australia/Adelaide');
 $date = new DateTime('now', $timezone);
 echo $date->format('d M Y, H:i:s');
 # 18 Aug 2022, 22:46:29

Example: DateTime::setTimezone() method to specify timezone later

You can specify or change the time zone of a DateTime object later by passing a DateTimeZone object as an argument to the setTimezone() method:

<?php
 $timezone = new DateTimeZone('Australia/Adelaide');
 $date = new DateTime('now', $timezone);
 echo $date->format('d M Y, H:i:s') . '<br>';
 # 13 Aug 2022, 13:44:31
 
 $timezone = new DateTimeZone('America/Eirunepe');
 $date->setTimezone($timezone);
 echo $date->format('d M Y, H:i:s');
 # 12 Aug 2022, 23:14:31

Example: DateTime::getTimezone() method to get timezone information

The getTimezone() method returns a DateTimeZone object representing the DateTime object’s time zone:

<?php
 $date = new DateTime();
 $timezone = $date->getTimezone();
 echo $timezone->getName();
 # Prints: Europe/Berlin

DateTimeZone::getLocation

How to get location information for a timezone?

You can get the location information from the time zone object using the getLocation() method. This method returns an associative array that provides the country code of origin of the time zone, longitude & latitude, and some comments.

<?php
 $timezone = new DateTimeZone('Asia/Kolkata');
 $location = $timezone->getLocation();
 foreach ($location as $k => $v){
  echo "$k: $v <br>";
 }
 # country_code: IN
 # latitude: 22.53333
 # longitude: 88.36666
 # comments:

Use the following code if you want to retrieve location information from a DateTime object:

<?php
 $date = new DateTime();
 $timezone = $date->getTimezone();
 $location = $timezone->getLocation();
 foreach ($location as $k => $v){
  echo "$k: $v <br>";
 }
 # country_code: DE
 # latitude: 52.5
 # longitude: 13.36666
 # comments: Germany (most areas)

You can also get the name of the timezone by using the getName() method:

<?php
 $date = new DateTime();
 $timezone = $date->getTimezone();
 echo $timezone->getName();
 # Europe/Berlin

DateTimeZone::getOffset

How to get the timezone offset from UTC (GMT)

The getOffset() method returns the offset from UTC (Universal Coordinated Time) in seconds:

<?php
 $date = new DateTime();
 $timezone = new DateTimeZone('Asia/Kolkata');
 $offset = $timezone->getOffset($date);
 echo $offset . ' seconds <br>'; # 19800 seconds
 echo $offset / 3600 . ' hour(s)'; # 5.5 hour(s)

DateTimeZone::getTransitions

How to get all transitions for the timezone?

The getTransitions() method returns a multidimensional array containing historical and future dates and times of switching to and from daylight saving time. The returned array structure is:

ts key: Unix timestamp
time key: time string
offset key: UTC offset in seconds
isdst key: True if daylight saving time is active, false otherwise.
abbr key: Timezone abbreviation

<?php
 $timezone = new DateTimeZone('Asia/Karachi');
 $transitions = $timezone->getTransitions();
 print_r($transitions);

The above code prints the following result:

The result enables you to calculate whether daylight saving time is in force at a specific date and time. You can limit the range of results by providing the two optional timestamps: $timestampBegin and $timestampEnd, see the following example:

<?php
 $timestampBegin = strtotime(' 01 jan 2005');
 $timestampEnd   = strtotime ('01 jan 2015');
 
 $timezone = new DateTimeZone('Asia/Karachi');
 $transitions = $timezone->getTransitions(
                 $timestampBegin, $timestampEnd);
 print_r($transitions);

The following output prints on the browser:

DateTimeZone::listAbbreviations

How to get DST, UTC offset, and the timezone name.

The listAbbreviations() is a static method, it returns a multidimensional array. The array lists dst (daylight saving time), offset (UTC offset in seconds), and timezone_id for each time zone (e.g. GMT, EDT, EST etc.):

<?php
 $all_timezones = DateTimeZone::listAbbreviations();
 print_r($all_timezones); # Prints all abbreviations
 
 $edt = $all_timezones['edt'];
 print_r($edt); # Prints Eastern Daylight Time information

The time zone abbreviations with DST, UTC offset, and the timezone names.

DateTimeZone::listIdentifiers

How to get all defined timezone identifiers?

The listIdentifiers() is a static method, it returns an array of all PHP time zone identifiers.

<?php
 $all_identifiers = DateTimeZone::listIdentifiers();
 print_r($all_identifiers);
 /* Prints: 
 Array (
    [0] => Africa/Abidjan
    [1] => Africa/Accra
    [2] => Africa/Addis_Ababa
    [3] => Africa/Algiers
    [4] => Africa/Asmara
	...
	...
    [422] => Pacific/Tongatapu
    [423] => Pacific/Wake
    [424] => Pacific/Wallis
    [425] => UTC
 )

Get time zone identifiers for a specific region

The listIdentifiers() method takes two arguments:

$timezoneGroup
This argument accepts one of the DateTimeZone class constants (or a combination) listed below to return time zone identifiers for a specific region.
$countryCode
The second argument accepts a two-letter (uppercase) country code to return a time zone identifier for a specific country. To get an identifier for a specific country you must provide the DateTimeZone::PER_COUNTRY in the first argument.

List of DateTimeZone class constants:

DateTimeZone::AFRICA
DateTimeZone::AMERICA
DateTimeZone::ANTARCTICA
DateTimeZone::ARCTIC
DateTimeZone::ASIA
DateTimeZone::ATLANTIC
DateTimeZone::AUSTRALIA
DateTimeZone::EUROPE
DateTimeZone::INDIAN
DateTimeZone::PACIFIC
DateTimeZone::UTC
DateTimeZone::ALL
DateTimeZone::ALL_WITH_BC
DateTimeZone::PER_COUNTRY

Example: Get time zone identifiers for the Australia

<?php
 $i = DateTimeZone::listIdentifiers(DateTimeZone::AUSTRALIA);
 foreach ($i as $identifier){
  echo "$identifier <br>";
 }
 /* Prints: 
Australia/Adelaide
Australia/Brisbane
Australia/Broken_Hill
Australia/Currie
Australia/Darwin
Australia/Eucla
Australia/Hobart
Australia/Lindeman
Australia/Lord_Howe
Australia/Melbourne
Australia/Perth
Australia/Sydney  */

Get time zone identifier by country

The second argument of listIdentifiers() method accepts a two-letter (uppercase) country code to return a time zone identifier for a specific country. To get an identifier for a specific country you must provide the DateTimeZone::PER_COUNTRY in the first argument:

Example: Get time zone identifiers for USA

<?php
 $i = DateTimeZone::listIdentifiers(DateTimeZone::PER_COUNTRY, 'US');
 foreach ($i as $identifier){
  echo "$identifier <br>";
 }
 /* Prints: 
America/Adak
America/Anchorage
America/Boise
America/Chicago
America/Denver
America/Detroit
America/Indiana/Indianapolis
America/Indiana/Knox
America/Indiana/Marengo
America/Indiana/Petersburg
America/Indiana/Tell_City
America/Indiana/Vevay
America/Indiana/Vincennes
America/Indiana/Winamac
America/Juneau
America/Kentucky/Louisville
America/Kentucky/Monticello
America/Los_Angeles
America/Menominee
America/Metlakatla
America/New_York
America/Nome
America/North_Dakota/Beulah
America/North_Dakota/Center
America/North_Dakota/New_Salem
America/Phoenix
America/Sitka
America/Yakutat
Pacific/Honolulu  */

Example: Get time zone identifiers for China

<?php
 $i = DateTimeZone::listIdentifiers(DateTimeZone::PER_COUNTRY, 'CN');
 foreach ($i as $identifier){
  echo "$identifier <br>";
 }
 /* Prints: 
Asia/Shanghai
Asia/Urumqi  */

The Date and Time Tutorials: