Calculer entre deux date en VBA

Private Sub CommandButton1_Click()

    Unload Me

End Sub

Private Sub TextBox1_Exit(ByVal Cancel As MSForms.ReturnBoolean)

    DiffDate
    
End Sub

Private Sub TextBox2_Exit(ByVal Cancel As MSForms.ReturnBoolean)

    DiffDate

End Sub


Private Sub DiffDate()
    
    On Error GoTo Fin 'gère l'erreur du textbox par encore rempli
    
    TextBox3 = DateDiff("d", TextBox1.Value, TextBox2.Value, 2, 2) & " jours"
    TextBox4 = DateDiff("m", TextBox1.Value, TextBox2.Value, 2, 2) & " Mois"
    TextBox5 = DateDiff("ww", TextBox1.Value, TextBox2.Value, 2, 2) & " Semaine(s)"
    TextBox6 = DateDiff("q", TextBox1.Value, TextBox2.Value, 2, 2) & " Trimestre(s)"
    TextBox7 = DateDiff("yyyy", TextBox1.Value, TextBox2.Value, 2, 2) & " Année(s)"
    TextBox8 = DateDiff("h", TextBox1.Value, TextBox2.Value, 2, 2) & " Heure(s)"
    TextBox9 = DateDiff("n", TextBox1.Value, TextBox2.Value, 2, 2) & " Minutes(s)"
    TextBox10 = DateDiff("s", TextBox1.Value, TextBox2.Value, 2, 2) & " Seconde(s)"
    
Fin:

End Sub

Private Sub CommandButton1_Click()

    Unload Me

End Sub

Private Sub TextBox1_Exit(ByVal Cancel As MSForms.ReturnBoolean)
    
    If TextBox1.Text <> "" And TextBox2.Text <> "" Then DiffDate
    
End Sub

Private Sub TextBox2_Exit(ByVal Cancel As MSForms.ReturnBoolean)

    If TextBox1.Text <> "" And TextBox2.Text <> "" Then DiffDate

End Sub


Private Sub DiffDate()

    Dim DateDebut As Date
    Dim DateFin As Date
    
    'gère l'erreur de la date entrée de cette façon : dimanche 24 février 2013
    On Error Resume Next
    DateDebut = CDate(TextBox1.Value)
    
    'reconstitue la date de façon à ce que le compilateur puisse la reconnaître
    If Err.Number <> 0 Then DateDebut = Deformater(TextBox1.Value)
    
    'remet à 0 pour la date suivante
    Err.Number = 0
    DateFin = CDate(TextBox2.Value)
    
    'idem que plus haut
    If Err.Number <> 0 Then DateFin = Deformater(TextBox2.Value)
    
    On Error GoTo 0 'supprime le gestionnaire
    
    On Error GoTo Fin 'remet en place un gestionnaire pour gérer l'erreur du textbox par encore rempli
    
    TextBox3 = DateDiff("d", DateDebut, DateFin, 2, 2) & " jours"
    TextBox4 = DateDiff("m", DateDebut, DateFin, 2, 2) & " Mois"
    TextBox5 = DateDiff("ww", DateDebut, DateFin, 2, 2) & " Semaine(s)"
    TextBox6 = DateDiff("q", DateDebut, DateFin, 2, 2) & " Trimestre(s)"
    TextBox7 = DateDiff("yyyy", DateDebut, DateFin, 2, 2) & " Année(s)"
    TextBox8 = DateDiff("h", DateDebut, DateFin, 2, 2) & " Heure(s)"
    TextBox9 = DateDiff("n", DateDebut, DateFin, 2, 2) & " Minutes(s)"
    TextBox10 = DateDiff("s", DateDebut, DateFin, 2, 2) & " Seconde(s)"
    
Fin:

End Sub

Function Deformater(LaDate As String) As Date

    Dim Jour As Long
    Dim Mois As String
    Dim Annee As Long
        
    Select Case LCase(Split(LaDate, " ")(2))
    
        Case "janvier": Mois = 1
        Case "février": Mois = 2
        Case "mars": Mois = 3
        Case "avril": Mois = 4
        Case "mai": Mois = 5
        Case "juin": Mois = 6
        Case "juillet": Mois = 7
        Case "août": Mois = 8
        Case "septembre": Mois = 9
        Case "octobre": Mois = 10
        Case "novembre": Mois = 11
        Case "décembre": Mois = 12
        
    End Select
        
    Jour = Split(LaDate, " ")(1)
    
    Annee = Split(LaDate, " ")(3)
    
    Deformater = CDate(Jour & "/" & Mois & "/" & Annee)

End Function