Private Sub DataGridView1_ColumnWidthChanged(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.DataGridViewColumnEventArgs) Handles _
  DataGridView1.ColumnWidthChanged
    If e.Column.Name = "Ende" Then
        Select Case e.Column.Width
            Case Is >= 110 : e.Column.DefaultCellStyle.Format = "ddd" & _
              "dd.MM.yyyy HH:mm"
            Case Is >= 90 : e.Column.DefaultCellStyle.Format = "ddd dd.MM. HH:mm"
            Case Is >= 78 : e.Column.DefaultCellStyle.Format = "dd.MM. HH:mm"
            Case Is >= 68 : e.Column.DefaultCellStyle.Format = "ddd HH:mm"
            Case Else : e.Column.DefaultCellStyle.Format = "HH:mm"
        End Select
    End If
End Sub