you can add code on worksheet change event
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Count = 1 Then
If Target.Column = 3 And Target.Value <> "" Then
Target.Offset(0, 2).Value = Target.Value + Target.Offset(0,
1).Value
Target.Offset(0, 2).Num
Yes
Keep in mind that the DATE is simply a number, displayed in Date format.
So, your date: 1/1/2013
is really 41275 (the number of days since 1/1/1900)
So, your "Expiration Date" is
41275 + 30, or 41305
which is DISPLAYED as 1/31/2013
a Macro would would similarly:
Sub ExpDate()
Dim