Sub AddDatedSheetNames()
Dim X As Long, NextSheetName As String
Worksheets("Apr-09").Activate
For X = 1 To 11
NextSheetName = Format(DateAdd("m", 1, CDate("28-" & ActiveSheet.Name)), "mmm-yy")
ActiveSheet.Copy After:=ActiveSheet
ActiveSheet.Name = NextSheetName
Next
End Sub