Sub YearByMonth()
 Dim intSheetCount As Integer
 Workbooks.Add
 Worksheets.Add Count:=12 - ActiveWorkbook.Worksheets.Count
 For intSheetCount = 1 To 12
 Worksheets(intSheetCount).Name = Format(DateSerial(1, intSheetCount, 1), "mmm")
 Next intSheetCount
End Sub