Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
If Intersect(Target, [A1]) Is Nothing Then Exit Sub
Dim dat$
Cancel = True
On Error Resume Next
1 dat = InputBox("Entrez une nouvelle date :", , dat)
If dat = "" Then Exit Sub
If CDate(dat) < IIf(ThisWorkbook.Date1904, 1462, 2) Then GoTo 1
Application.EnableEvents = False
[A1] = Application.Proper(Format(dat, "mmmm-yyyy"))
Application.EnableEvents = True
End Sub