Public Class frmKalender
    Private Sub MonthCalendar1_DateChanged(sender As Object, e As DateRangeEventArgs) Handles MonthCalendar1.DateChanged
        Me.MaskedTextBox1.Text = Me.MonthCalendar1.SelectionStart
    End Sub

    Private Sub frmKalender_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.MaskedTextBox1.Text = Now.ToShortDateString
    End Sub

    Private Sub btnOK_Click(sender As Object, e As EventArgs) Handles btnOK.Click
        DialogResult = DialogResult.OK
        Me.Close()
    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        DialogResult = DialogResult.Abort
    End Sub

    Private Sub MaskedTextBox1_MaskInputRejected(sender As Object, e As MaskInputRejectedEventArgs) Handles MaskedTextBox1.MaskInputRejected

    End Sub

    Private Sub MaskedTextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles MaskedTextBox1.KeyDown
        If e.KeyCode = Keys.Enter Then Button1_Click(sender, e)
    End Sub
End Class