Adding a Pause Button into a time on excel

Option Explicit

Dim CountDown As Date
Sub Timer()
    CountDown = Now + TimeValue("00:00:01")
    Application.OnTime CountDown, "Reset"
End Sub

Sub Reset()
Dim count As Range
    Set count = [A1] ' A1 contains the number of seconds for the countdown.
        count.Value = count.Value - 1
    If count <= 0 Then
        MsgBox "Countdown complete."
        Exit Sub
    End If
        Call Timer
End Sub

Sub DisableTimer()
    On Error Resume Next
    Application.OnTime EarliestTime:=CountDown, Procedure:="Reset", Schedule:=False
End Sub