Module Timer pada VBA Excel

Public Interval As Date
Sub start_timer()
     Dim Detik As Integer
     Detik = Int((Rnd * 5) + 1)
     Interval = Now + TimeValue("00:00:" & Detik)
     Application.OnTime Interval, "start_timer"
    'Memanggil prosedur / sub yang berisi perintah yang diinginkan 
    Sheet1.Kirim_Pesan
 End Sub
 Sub stop_timer()
     Application.OnTime EarliestTime:=Interval, Procedure:="start_timer", Schedule:=False
 End Sub