Function NuméroDeSemaineISO(d1 As Date) As Integer
'Daniel Maher/excelabo
'Correction par ROGER2327
Dim madate As Long
madate = DateSerial(Year(d1 - Weekday(d1 - 1) + 4), 1, 3)
NuméroDeSemaineISO = Int((d1 - madate + Weekday(madate) + 5) / 7)
End Function