List of Supported Timezones
PHP Manual

List of timezones in the group 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/San_Juan America/Argentina/Tucuman
America/Argentina/Ushuaia America/Aruba America/Asuncion America/Atikokan America/Atka
America/Bahia 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/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_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/La_Paz
America/Lima America/Los_Angeles America/Louisville America/Maceio America/Managua
America/Manaus America/Marigot America/Martinique America/Mazatlan America/Mendoza
America/Menominee America/Merida 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/Center
America/North_Dakota/New_Salem 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/Santiago America/Santo_Domingo America/Sao_Paulo
America/Scoresbysund America/Shiprock 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