     
     fileprivate func updateTimer() {
         
-        guard let timerStartedOn = timerStartedOn else { return }
+        guard let timerElapsesOnDate = timerElapsesOnDate else { return }
         
-        let interval = DateInterval(start: timerStartedOn, end: Date())
+        let interval = DateInterval(start: Date(), end: timerElapsesOnDate)
         
         let minutes = Int(interval.duration) / 60 % 60
         let seconds = Int(interval.duration) % 60

        currentState = currentState == .idle ? .active : .idle
        
        if currentState == .active {
            timerStartedOn = Date()
            timer.start(0.25, callDelegateWhenExpired: self)
        }
        

    private let inactiveOffset: CGFloat = 25
    
    fileprivate let timer = SystemTimer()
    private var timerElapsesOnDate: Date?
    private var activeDeveloper: Developer = .left
    fileprivate var currentState: CurrentState = .idle
    
