Stop macro based on cell value

Command button linked to Recalc macro. I am looking to add code to the below to stop watch based on text in a certain sheet

Dim SchedRecalc As Date
Sub Recalc()
Range("A1").Value = Format(Now, "dd-mmm-yy")
Range("A2").Value = Format(Time, "hh:mm:ss AM/PM")
Call SetTime

End Sub

Sub SetTime()
SchedRecalc = Now + TimeValue("00:00:06")
Application.OnTime SchedRecalc, "Recalc"

End Sub

Sub Disable()
On Error Resume Next
Application.OnTime EarliestTime:=SchedRecalc, Procedure:="Recalc", Schedule:=False
End Sub

Thanks Bernie, I'll give it a try