toTime = function (expires) {
            var time = expires == 0 ? 0 : ((new Date).getTime() + expires * 86400000);
            // convert to duotricemary notation
            return time.toString(32);
        }
Convert expire time's format from day to millisecond
@param  {Number} expires Expire days
@return {String}         Expire time in duotricemary notation