Private Function SumarMes(fecha As Date)
Dim f As Variant
On Error GoTo xError
f = Split(Format(fecha, "dd/mm/yyyy"), "/")
If f(1) < 12 Then
f(1) = f(1) + 1
Else
f(1) = 1
f(2) = f(2) + 1
End If
SumarMes = DateValue(f(0) & "/" & f(1) & "/" & f(2))
Exit Function
xError:
SumarMes = #1/1/1900#
End Function