Change date format inside textbox userform

[sofas]

Welcome. I have this code to enter the date into a textbox in the format "dd-mm-yyyy
I want to change it to "yyyy-mm-dd
Can I do that?

Sub CtrL_Keydown(ByVal TxtB As MSForms.TextBox, ByVal KeyCode As MSForms.ReturnInteger, ByVal mask As String, Optional dat As Boolean)
    If KeyCode >= 48 And KeyCode <= 57 Then KeyCode = KeyCode + 48
    With TxtB
        Xl = .SelLength: If Xl = 0 Then Xl = 1
        .Value = IIf(.Value = "", mask, .Value): If KeyCode = 8 And Xl > 1 Then KeyCode = 46
        T = .Value: .SelStart = IIf(T = mask, InStr(1, mask, "_") - 1, .SelStart): X = .SelStart:
        Select Case KeyCode
        Case 96 To 105
            If dat Then Xl = 2
            If X = Len(mask) Then KeyCode = 0: Exit Sub
            If Mid(T, X + 1, 1) <> "_" And Not Mid(T, X + 1, 1) Like "[0-9]" Then X = InStr(T, "_") - 1
            Mid(T, X + 1, Xl) = Chr(KeyCode - 48) & Mid(mask, X + 2, Xl - 1): Xl = 0
            X = IIf(Mid(T, X + 1, 1) <> "_", InStr(T, "_") - 1, X + 1)
            If dat Then
                If Val(T) > 31 Or Val(Mid(T, 1, 1)) > 3 Then X = 0: Xl = 2: Mid(T, 1, 2) = Mid(mask, 1, 2): Beep
                If Val(Mid(T, 4, 2)) > 12 Or Val(Mid(T, 4, 1)) > 1 Then Mid(T, 4.2) = Mid(mask, 4, 2): X = 3: Xl = 2: Beep
                d = Mid(T, 1, 2): M = Mid(T, 4, 2): a = Mid(T, 7, 4)
                If IsDate(d & "/" & M) And Not IsDate(d & "/" & M & "/2000") Then Mid(T, 4, 2) = Mid(mask, 4, 2): X = 3: Xl = 2: Beep: KeyCode = 0
                If X = 10 And Not IsDate(T) Then Mid(T, 7, 10) = Mid(mask, 7, 10): X = 6: Xl = 4: Beep
            End If
        Case 8:
            If X = 0 Then KeyCode = 0:: .Value = "": Exit Sub Else Mid(T, X, 1) = Mid(mask, X, 1): X = X - 1: Xl = 0
            If T = mask Then T = ""
        Case 46:
            If X = 10 Then Exit Sub Else Mid(T, X + 1, Xl) = Mid(mask, X + 1, Xl): X = X: Xl = 0:
            If T = mask Then T = ""
        Case Else: KeyCode = 0
        End Select
        .Value = T
        If X > Len(mask) Or X = -1 Then X = Len(mask)
        .SelStart = X: .SelLength = 0: KeyCode = 0
    End With
    KeyCode = 0
End Sub

 

[Akuini]

@sofas
It seems like you want to validate the input as each character is typed. Is that really necessary? It seems quite complicated.
How about letting the user to input the date completely, and then validating it by clicking a command button?
Here's an example: link