Private Sub Calendar1_Click()
    With Calendar1
        ActiveCell = .Value
        .Visible = False
    End With
End Sub
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
    If Target.Column = 13 And Target.Row > 3 Or Target.Column = 14 And
Target.Row > 3 Then
        If IsDate(Target) Then
            Calendar1.Value = Target
        Else
            Calendar1.Today
        End If
        Calendar1.Visible = -20
        Calendar1.Top = ActiveCell.Top + ActiveCell.Height
        Calendar1.Left = ActiveCell.Left + Cells(ActiveCell.Rows.Count,
1).Left
    Else
        Calendar1.Visible = 0
    End If
End Sub

Private Sub Calendar1_Click()
    With Calendar1
        ActiveCell = .Value
        .Visible = False
    End With
End Sub
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
    If Target.Column = 13 And Target.Row > 3 Or Target.Column = 14 And
Target.Row > 3 Then
        If IsDate(Target) Then
            Calendar1.Value = Target
        Else
            Calendar1.Today
        End If
        Calendar1.Visible = -20
        Calendar1.Top = ActiveCell.Top + ActiveCell.Height
        Calendar1.Left = ActiveCell.Left + Cells(ActiveCell.Rows.Count,
1).Left
    Else
        Calendar1.Visible = 0
    End If
End Sub