ขอคำแนะนำ Select Date BETWEEN [VB.NET] และ SQL SERVER ครับ

 Private Sub runreport()



        If cn.State = ConnectionState.Closed Then cn.Open()



        If Checkday.Checked Then
            Dim sql As String = "SELECT * FROM F_ree WHERE  redate between '" & Format(D1.Value, "yyyy/mm/dd") & "' and '" & Format(D2.Value, "yyyy/mm/dd") & " ORDER BY redate ASC'"
        Else
            allday.Checked = True

        End If


        Dim adapter As New SqlDataAdapter()
        Dim dataset As New DataSet()
        adapter.Fill(dataset, "F_ree")
        DR = cmd.ExecuteReader
        Dataallbuy.Rows.Clear()

        While (DR.Read() = True)

            Dataallbuy.Rows.Add(DR(0), DR(1), DR(2), DR(3), DR(4))
        End While
        cn.Close()


    End Sub