Timer calculation in Access Database

Hi Experts,
I have a question about the calculation time problem in Access Database for Automatically close the database if the database is idle for a period of time.
How do I calaulate for hour(s)?  I would like to set to if idle for 3 hours then close the database automaticaly.

Is this correct for Calculate mintue? -- > ExpiredMinutes = (ExpiredTime / 1000) / 60    

here is my code in the calculation part:

'I set the timer Interval to 1000
ExpiredTime = ExpiredTime + Me.TimerInterval


    ExpiredMinutes = (ExpiredTime / 1000) ' this is for 1 second
    Me.txtIdleTime = ExpiredMinutes
   
If ExpiredMinutes >= 10 Then  ' this is for 10 minutes
   ExpiredTime = 0
   Application.Quit acQuitSaveAll
End If

Thanks,