Displaying total runtime of Macro

[unmarkedhelicopter]

Minutes and milliseconds ?
Surely you mean mm:ss.sss ??? minutes, seconds and milliseconds ?
This sort of thing IS generic, we ALL use this sort of thing during testing to identify bottlenecks and find which of a few options is 'that' bit quicker.
There is a typo in the last code you were given.

Always check your code,
Something is wrong if you are always getting the same result.
Sounds like a variable NEVER being updated

Try :-

Sub Timed_Code() 
Dim timet1 As Double 
timet1 = Now 
' Run Your Code Here
MsgBox "EXPECTED macro completed at " & Format$(Now, "dd/mm/yyyy h:mm:ss am/pm") & _
vbcrlf & "The entire process took " & Format$((Now - timet1) / 86400, "h:mm:ss") & " h:mm:ss" 
End Sub

Each case is different and thus requires SOME manual tweaking, if you want mm:ss.sss then I'll know you up some other code.