Private Sub Worksheet_Change(ByVal Target As Range)
Dim nom$, dat$, i As Variant
nom = Target(1)
If Target.Row > 1 Then dat = Target(0, 1)
If Not IsDate(dat) Then Exit Sub
With Sheets("historiqu")
i = Application.Match(CDbl(CDate(dat)), .Columns(3), 0)
If IsNumeric(i) Then .Cells(i, 5) = nom
End With
End Sub