Option Explicit Function IsLongYear(ByVal Year As Integer) As Boolean Select Case vbThursday Case VBA.DatePart("w", VBA.DateSerial(Year, 1, 1)), _ VBA.DatePart("w", VBA.DateSerial(Year, 12, 31)) IsLongYear = True End Select End Function Sub Main() 'test Dim l As Long For l = 1990 To 2021 Select Case l Case 1992, 1998, 2004, 2009, 2015, 2020 Debug.Assert IsLongYear(l) Case Else Debug.Assert Not IsLongYear(l) End Select Next l End Sub