How to set up a time counter between two clicks in Excel - excel

Question

I'm trying to make a VBA code that allows me to calculate the time ellapsed between two clicks/buttons.
Here is the scenario I'm looking for :
I select an empty cell in the column Time
I click on the START button (to start the counter)
I click on the STOP button (to stop the counter)
The ellapsed time (in the format "hh:mm:dd") has to be put in the selected cell in step 1
Expected output :
I started making a code for the START button but I don't know how the one's for the STOP button.
Sub CalculateTime()
Dim startTime As Double
Dim TimeElapsed As String
startTime = Timer
TimeElapsed = Format((Timer - startTime) / 86400, "hh:mm:ss")
ActiveCell.Value = TimeElapsed
End Sub
Do you have any suggestions, please ?
Any help will be appreciated !
EDIT :
Here is the code of my two subs :
Sub StartButton()
Call CalculateTime(True)
End Sub
'**************************************
Sub StopButton()
ActiveCell.Value = CalculateTime(False)
End Sub

Answer 1

There are various ways to tackle this. One way is to use a global variable (startTime) which is set in your Start button click event. Your Stop button then executes your method and (sans the startTime = Time line obviously).
But I prefer to avoid global variables, so therefore you could rewrite your Sub as a Function and call it twice. Once from the Start button: Call CalculateTime(True). And once from the Stop button: ActiveCell.Value = CalculateTime(False)
Function CalculateTime(ByVal bolStart As Boolean) As String
' Declaring a local variable as Static preserves their value between calls
' of the method.
Static startTime As Double
If bolStart = True Then
' This is the start of the measurement, we simply store the time
startTime = Timer
Else
' This is the end of the measurement, so we calculate the time elapsed
' and return it as a string.
CalculateTime = Format$((Timer - startTime) / 86400, "hh:mm:ss")
End If
End Function