How are you entering your to and from date ?  It sounds like you want command.date >= from date and command.date <= to date.   In your formula, what is the value of "My Parameter" ?

Page1:

From Date: TXTBOX1   To Date: TXTBOX2

BTNSUBMIT-CLICK
{
server.transfer("page2.aspx");
}


Page 2:

 if (PreviousPage != null)
        {
            TextBox txt1 = PreviousPage.FindControl("TXTBOX1") as TextBox;
            TextBox txt2 = PreviousPage.FindControl("TXTBOX2") as TextBox;


            if (txt1.Text.Length != 0 && txt2.Text.Length != 0)
            {

             ReportDocument cryRpt = new ReportDocument();
             cryRpt.Load("MyReport.rpt");

                ParameterFieldDefinitions crParameterFieldDefinitions;
                ParameterFieldDefinition crParameterFieldDefinition;
                ParameterValues crParameterValues = new ParameterValues();
                ParameterDiscreteValue crParameterDiscreteValue = new         
                ParameterDiscreteValue();

                crParameterDiscreteValue.Value = txt1.Text + txt2.Text;
                crParameterFieldDefinitions =
                cryRpt.DataDefinition.ParameterFields;
                crParameterFieldDefinition =
                crParameterFieldDefinitions["MyParameter"];
                crParameterValues = crParameterFieldDefinition.CurrentValues;

                crParameterValues.Clear();
                crParameterValues.Add(crParameterDiscreteValue);
                crParameterFieldDefinition.ApplyCurrentValues(crParameterValues);

                CrystalReportViewer1.ReportSource = cryRpt;

            }

         }


Formula In Formula Editor:

{Command.Date} >= {?MyParameter} and {Command.Date} <= {?MyParameter}