Private Sub CommandButton1_Click()
With TextBox10
If Not IsDate(.Value) Then MsgBox "Date non valide !", 48: _
.SetFocus: .SelStart = 0: .SelLength = Len(.Value): Exit Sub 'sécurité
Sheets("configuration").Range("date_debut_projet") = CDate(.Value)
Sheets("configuration").Range("A1") = CDate(.Value)
'date_sans_format
Sheets("configuration").Range("date_sans_format").NumberFormat = "General" 'format Standard
Sheets("configuration").Range("date_sans_format") = CDbl(CDate(.Value))
End With
Unload Me
End Sub