Create timer to check running time for "Master" macro

Hell0! I hope anyone can help me with the following problem:
How do I create a timer in a master macro? I got total 21 macros in one Master and I want to check the duration time for the whole master to finish.

I appreciate any help.

Sub x()

   Dim t As Single
   Dim x As Long
   
   t = Timer
   
   Do While x < 100000
      DoEvents
      x = x + 1
   Loop
   
   MsgBox "Time elapsed: " & Timer - t & " seconds"
   
End Sub

Thank you so much! I tried to create the macro, then set in first in my "Master" macro, but got an error; "timer needs to be a function".

The sample code I posted works - so any issues are on your side. However, without seeing your code it's a pure guessing game...