List of Supported Timezones
PHP Manual

Pacific

Pacific
Pacific/Apia Pacific/Auckland Pacific/Chatham Pacific/Easter Pacific/Efate
Pacific/Enderbury Pacific/Fakaofo Pacific/Fiji Pacific/Funafuti Pacific/Galapagos
Pacific/Gambier Pacific/Guadalcanal Pacific/Guam Pacific/Honolulu Pacific/Johnston
Pacific/Kiritimati Pacific/Kosrae Pacific/Kwajalein Pacific/Majuro Pacific/Marquesas
Pacific/Midway Pacific/Nauru Pacific/Niue Pacific/Norfolk Pacific/Noumea
Pacific/Pago_Pago Pacific/Palau Pacific/Pitcairn Pacific/Ponape Pacific/Port_Moresby
Pacific/Rarotonga Pacific/Saipan Pacific/Samoa Pacific/Tahiti Pacific/Tarawa
Pacific/Tongatapu Pacific/Truk Pacific/Wake Pacific/Wallis Pacific/Yap

List of Supported Timezones
PHP Manual