     }
 }
 
-let DAY: TimeInterval = 60*60*24
 let DAYS_IN_WEEK: Int = 7
-let WEEK: TimeInterval = DAY*TimeInterval(DAYS_IN_WEEK)
 
 extension Date {
     

    }
    
    func daysAfter(_ days: Int) -> Date? {
        guard let startOfDay = self.startOfDay() else { return nil }
        return startOfDay.addingTimeInterval(DAY*TimeInterval(days))
    }
    
    func dayAfter() -> Date? {

        }
    }
    
    var daysLeftTillNextWeek: Int {
        switch self {
        case .monday:   return 7
        case .tuesday:  return 6
