Multiple timers on one Sheet - vba

Question

Modified [Halfway there]
Thank you YowE3K, after your comments the code has been modified but yet it is not working as it should be...
Both timers run independently and fine but only when they run separately. At the very moment when I turn both going, they start counting on every 2 seconds instead of one as it should be. I know it is maybe related to this part "Application.OnTime SchdTime + OneSec, "Sheet1.setImmediate" but I don't know how to specify the cell here. Currently they both add one second to Sheet1 when they go together.
Additionally the issue with the timers starting from 00:00:00 after reopening the document stays.
Here is the code - please note that this one is for ToggleButtons:
Dim StopTimer As Boolean
Dim SchdTime As Date
Dim Etime As Date
Dim SchdTime2 As Date
Dim Etime2 As Date
Const OneSec As Date = 1 / 86400#
Private Sub Start_Stop_1_Click()
If Start_Stop_1 = True Then
StopTimer = False
SchdTime = Now()
[K3].Value = Format(Etime, "hh:mm:ss")
Application.OnTime SchdTime + OneSec, "Sheet1.setImmediate"
Else
StopTimer = True
Beep
End If
End Sub
Private Sub Start_Stop_2_Click()
If Start_Stop_2 = True Then
StopTimer = False
SchdTime2 = Now()
[K4].Value = Format(Etime2, "hh:mm:ss")
Application.OnTime SchdTime2 + OneSec, "Sheet1.setImmediate"
Else
StopTimer = True
Beep
End If
End Sub
Sub setImmediate()
If Start_Stop_1 = True Then
[K3].Value = Format(Etime, "hh:mm:ss")
SchdTime = SchdTime + OneSec
Application.OnTime SchdTime, "Sheet1.setImmediate"
Etime = Etime + OneSec
Else: StopTimer = True
'Don't reschedule update
End If
If Start_Stop_2 = True Then
[K4].Value = Format(Etime2, "hh:mm:ss")
SchdTime2 = SchdTime2 + OneSec
Application.OnTime SchdTime2, "Sheet1.setImmediate"
Etime2 = Etime2 + OneSec
Else: StopTimer = True
'Don't reschedule update
End If
End Sub