How to restrict values in Winforms MaskedTextbox

My requirement is that the user will enter a time ("HH:mm:ss") in masked text box and based on that time i am doing some functionalities. My problem is i can mask the time but i can't restrict the user to enter up to 23 for hours,59 for minutes and 59 for seconds. How to fix this.

C# Code

private void Form1_Load(object sender, EventArgs e)
 {
	maskTxtAlert1.Mask = "00:00:00";
        maskTxtAlert1.CutCopyMaskFormat = MaskFormat.ExcludePromptAndLiterals;
 }

 private void maskTxtAlert1_MaskInputRejected(object sender, MaskInputRejectedEventArgs e)
 {
            if (e.Position == maskTxtAlert1.Mask.Length)
           {
               string errorMessage = "You cannot add extra characters";
               toolTip1.ToolTipTitle = "Input Rejected - No more inputs allowed";
               toolTip1.Show(errorMessage, maskTxtAlert1, 12, 24, 2000);
               errorProvider1.BlinkStyle = ErrorBlinkStyle.AlwaysBlink;
               errorProvider1.SetError(maskTxtAlert1, errorMessage);
           }
           else
           {
               toolTip1.ToolTipTitle = "Input Rejected";
               string errorMessage = "You can only add numeric characters (0-9).";
               toolTip1.Show(errorMessage, maskTxtAlert1, 12, 24, 2000);
               errorProvider1.BlinkStyle = ErrorBlinkStyle.AlwaysBlink;
               errorProvider1.SetError(maskTxtAlert1, errorMessage);
           }
   }

 private void maskTxtAlert1_TypeValidationCompleted(object sender, TypeValidationEventArgs e)
 {
           MessageBox.Show("Enter Valid as One");
 }

Using a DateTimePickerFormat with .CustomFormat = "HH:mm:ss" is probably the best out of the box approach, but can be restrictive in terms of UI interaction.

For people coming here looking for adding validation to a MaskedTextBox, there are several good options.

Type Validation

If you still want automatic parsing, you can can add a ValidatingType and tap into the TypeValidationCompleted Event like this:

<!-- language: lang-vb -->

Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
        MaskedTextBox1.Mask = "00:00"
        MaskedTextBox1.ValidatingType = GetType(DateTime)
End Sub

Private Sub MaskedTextBox1_TypeValidationCompleted(sender As Object, e As TypeValidationEventArgs) _
    Handles MaskedTextBox1.TypeValidationCompleted
    If Not e.IsValidInput Then
        Me.validationToolTip.ToolTipTitle = "Invalid Time"
        Me.validationToolTip.Show("The time you supplied must be a valid time in the format HH:mm", sender)
    End If
End Sub

ValidatingType will tap into the public static Object Parse(string) method for each type it's passed. You can even pass in your own custom classes as long as they implement this signature

Custom Validation:

To provide your own custom validation, you can tap into the Validating Event like this:

<!-- language: lang-vb -->

Private Sub MaskedTextBox1_Validating(sender As System.Object, e As System.ComponentModel.CancelEventArgs) _
    Handles MaskedTextBox1.Validating
    Dim senderAsMask = DirectCast(sender, MaskedTextBox)
    Dim value = senderAsMask.Text
    Dim parsable = Date.TryParse(value, New Date)

    If Not parsable Then
        e.Cancel = True
        Me.validationToolTip.ToolTipTitle = "Invalid Time"
        Me.validationToolTip.Show("The time you supplied must be a valid time in the format HH:mm", sender)
    End If
End Sub

In this case, the validation implementation is still rather naive, but you could implement whatever logic you want to determine validity.

Notes:
If the CausesValidation property is set to false, the Validating and Validated events are suppressed.
If the Cancel property of the CancelEventArgs is set to true in the Validating event delegate, all events that would usually occur after the Validating event are suppressed.

For Bonus Points, hide the tooltip when the user starts typing again:

<!-- language: lang-vb -->

Private Sub MaskedTextBox1_KeyDown(ByVal sender As Object, ByVal e As KeyEventArgs) _
    Handles MaskedTextBox1.KeyDown
    Me.validationToolTip.Hide(sender)
End Sub