I use the code below to force all text to be in upper case. Now I need to
ensure the the number entered in column  Q is converted to a time format.
The time is always entered in the 24 hour format (18:45 = 6:45 pm, 0645 =
6:45 am) but the often forget the  " : ". These cells are not used for
calculations, but they still need to be in the proper format. so is there
any way to force  1845 to me converted to 18:45 or 645 to 06:45 while
ignoring a correctly entered number?

Private Sub Worksheet_Change(ByVal Target As Range)
   If Target.Cells.Count > 1 Then
       Exit Sub
   End If
   On Error GoTo ErrHandler:
   If Not Application.Intersect(Me.Range("G7:P2041"), Target) Is Nothing
Then
       If IsNumeric(Target.Value) = False Then
           Application.EnableEvents = False
           Target.Value = StrConv(Target.Text, vbUpperCase)
        End If
           Application.EnableEvents = True
       End If

ErrHandler:
   Application.EnableEvents = True
End Sub