Sub essai()
Dim i As Long
For i = 3 To 65536
if cells(i, 2)="" then exit for
If Cells(i, 2) = "années" Then Cells(i, 4).FormulaR1C1 = DateSerial(Year(Cells(i, 3)) + Cells(i, 1), Month(Cells(i, 3)), Day(Cells(i, 3)))
If Cells(i, 2) = "jour" Then Cells(i, 4).FormulaR1C1 = DateSerial(Year(Cells(i, 3)), Month(Cells(i, 3)), Day(Cells(i, 3)) + Cells(i, 1))
Next i
End Sub