Public Function Getyts(year As Integer, yue As Integer) As Integer
Dim n As Integer
If ((year Mod 4 = 0 And year Mod 100 <> 0) or year Mod 400 = 0) Then
n = 1
Else
n = 2
End If

If (n = 1 And yue = 2) Then
Getyts = 29
ElseIf (n = 2 And yue = 2) Then
Getyts = 28
End If

Select Case yue
Case 1, 3, 5, 7, 8, 10, 12
Getyts = 31
Case 4, 6, 9, 11
Getyts = 30
End Select
End Function

用法示例:Getyts(2009,1)=31