List of Supported Timezones
PHP Manual

America

America
America/Adak America/Anchorage America/Anguilla America/Antigua
America/Araguaina America/Argentina/Buenos_Aires America/Argentina/Catamarca America/Argentina/ComodRivadavia
America/Argentina/Cordoba America/Argentina/Jujuy America/Argentina/La_Rioja America/Argentina/Mendoza
America/Argentina/Rio_Gallegos America/Argentina/Salta America/Argentina/San_Juan America/Argentina/San_Luis
America/Argentina/Tucuman America/Argentina/Ushuaia America/Aruba America/Asuncion
America/Atikokan America/Atka America/Bahia America/Bahia_Banderas
America/Barbados America/Belem America/Belize America/Blanc-Sablon
America/Boa_Vista America/Bogota America/Boise America/Buenos_Aires
America/Cambridge_Bay America/Campo_Grande America/Cancun America/Caracas
America/Catamarca America/Cayenne America/Cayman America/Chicago
America/Chihuahua America/Coral_Harbour America/Cordoba America/Costa_Rica
America/Creston America/Cuiaba America/Curacao America/Danmarkshavn
America/Dawson America/Dawson_Creek America/Denver America/Detroit
America/Dominica America/Edmonton America/Eirunepe America/El_Salvador
America/Ensenada America/Fort_Nelson America/Fort_Wayne America/Fortaleza
America/Glace_Bay America/Godthab America/Goose_Bay America/Grand_Turk
America/Grenada America/Guadeloupe America/Guatemala America/Guayaquil
America/Guyana America/Halifax America/Havana America/Hermosillo
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/Indianapolis America/Inuvik America/Iqaluit America/Jamaica
America/Jujuy America/Juneau America/Kentucky/Louisville America/Kentucky/Monticello
America/Knox_IN America/Kralendijk America/La_Paz America/Lima
America/Los_Angeles America/Louisville America/Lower_Princes America/Maceio
America/Managua America/Manaus America/Marigot America/Martinique
America/Matamoros America/Mazatlan America/Mendoza America/Menominee
America/Merida America/Metlakatla America/Mexico_City America/Miquelon
America/Moncton America/Monterrey America/Montevideo America/Montreal
America/Montserrat America/Nassau America/New_York America/Nipigon
America/Nome America/Noronha America/North_Dakota/Beulah America/North_Dakota/Center
America/North_Dakota/New_Salem America/Ojinaga America/Panama America/Pangnirtung
America/Paramaribo America/Phoenix America/Port-au-Prince America/Port_of_Spain
America/Porto_Acre America/Porto_Velho America/Puerto_Rico America/Rainy_River
America/Rankin_Inlet America/Recife America/Regina America/Resolute
America/Rio_Branco America/Rosario America/Santa_Isabel America/Santarem
America/Santiago America/Santo_Domingo America/Sao_Paulo America/Scoresbysund
America/Shiprock America/Sitka America/St_Barthelemy America/St_Johns
America/St_Kitts America/St_Lucia America/St_Thomas America/St_Vincent
America/Swift_Current America/Tegucigalpa America/Thule America/Thunder_Bay
America/Tijuana America/Toronto America/Tortola America/Vancouver
America/Virgin America/Whitehorse America/Winnipeg America/Yakutat
America/Yellowknife      

List of Supported Timezones
PHP Manual