Excel - Add days to my coutdown clock

[Master_A]

Hi All!

I have made a countdown that works perfect with hours, minuts and seconds. But when I want to add days I get a problem. I have tryed to use numberformat = ("dd:hh:mm:ss") but somehow that does not work. Can anyone show how to integrate days to my countdown below?

Happy friday

Sub Nedtælling()


Workbooks("Alarm").Worksheets("Ark1").Range("a10") = Now
Workbooks("Alarm").Worksheets("Ark1").Range("a10").NumberFormat = ("hh:mm:ss")
Workbooks("Alarm").Worksheets("Ark1").Range("b10") = Now + TimeValue("00:00:15")
Workbooks("Alarm").Worksheets("Ark1").Range("b10").NumberFormat = ("hh:mm:ss")
Workbooks("Alarm").Worksheets("Ark1").Range("c10") = Range("b10") - Range("a10")
Workbooks("Alarm").Worksheets("Ark1").Range("c10").NumberFormat = ("hh:mm:ss")

Call Alarm

End Sub

Sub Alarm()

If Workbooks("Alarm").Worksheets("Ark1").Range("c10") > 0 Then
Workbooks("Alarm").Worksheets("Ark1").Range("c10") = Workbooks("Alarm").Worksheets("Ark1").Range("b10") - Now
Application.OnTime Now + TimeValue("00:00:01"), "Alarm"
End If



End Sub