how to get data between two dates in crystal report ?

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace cargo
{
    public partial class Employee_Information : Form
    {
        SQLConnection db = new SQLConnection();
        public Employee_Information()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                string str1 = "select * from employeeinfo where Date between '" + dateTimePicker1.Text + "' and '"+dateTimePicker2.Text+"' ";
                db.cmd.Connection = db.conn;
                db.cmd.CommandText = str1;
                SqlDataAdapter da = new SqlDataAdapter(str1,db.conn);
                da.Fill(db.ds, "employeeinfo ");
                CrystalReport1 cr = new CrystalReport1();
                cr.SetDataSource(db.ds.Tables[0]);
                crystalReportViewer1.ReportSource = cr;
                crystalReportViewer1.RefreshReport();
            }
            catch (Exception ex)
            {
                MessageBox.Show("error in query" + ex.Message);
            }
        

        }

        private void Employee_Information_Load(object sender, EventArgs e)
        {
            db.DBConnect();
        }

        private void Employee_Information_FormClosed(object sender, FormClosedEventArgs e)
        {
            db.DBClose();
        }

       
    }
}