//獲取時間戳
let today:NSDate =NSDate()
let dateFormatter = NSDateFormatter()
//以什麼樣的時間格式
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
let allday = dateFormatter.stringFromDate(today)
//1970到現在的秒數
let updatetimestamp = NSDate(timeIntervalSince1970: allday)