Dim datedeb As Date, datefin As Date
datedeb = Sheets("donnée").Range("B1")
datefin = Sheets("donnée").Range("B2")
numcol = 4
Select Case LCase(Sheets("donnée").Range("B3"))
Case "semaine"
pas = "ww"
Case "mois"
pas = "m"
Case "année"
pas = "yyyy"
End Select
While Format(datedeb, "yyyymmdd") < Format(datefin+1, "yyyymmdd")
Sheets("projet").Cells(1, numcol) = datedeb
Sheets("projet").Cells(2, numcol).FormulaR1C1 = "=WEEKNUM(R[-1]C)"
numcol = numcol + 1
datedeb = DateAdd(pas, 1, datedeb)
Wend