Set the timezone for the script: define('TIMEZONE', 'Asia/Calcutta'); // INDIA date_default_timezone_set(TIMEZONE); Get the default (script) timezone: date_default_timezone_get(); Get ini set timezone: ini_get('date.timezone'); Get timezone name: date("T"); Set timezone example: date_default_timezone_set('Europe/London'); // GMT GMT to IST conversion example: $event_length = 330; // IST is 5:30 ahead of GMT, so add 330 minutes $timestamp = strtotime(date("H:i:s")); $etime = strtotime("+$event_length minutes", $timestamp); $ist_time = date('H:i:s', $etime); echo '<br>'.'GMT - IST: '.$ist_time;