The general approach would be to use the ItemCreated event, capture the filtering item creation and access the desired controls to set their settings, like shown following article: https://docs.telerik.com/devtools/aspnet-ajax/controls/grid/how-to/Filtering/change-filter-items.

Here's an example I made for you:

Hi Marin Bratanov,

Thanks for your suggestion and comments. But I dont know why it is not working in my side. The only difference is I am creating the grid dynamically. And  I am using the telerik dll verion "RadControls for ASP.NET AJAX Q1 2013"

Placing my sample code for your referenc;

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Telerik.Web.UI;

namespace TelSample
{
    public partial class TelSample : System.Web.UI.Page
    {
        RadGrid RadGrid1;
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Page_Init(object sender, EventArgs e)
        {
            RadGrid1 = new RadGrid();
            RadGrid1.AutoGenerateColumns = false;
            createColumn();
            RadGrid1.DataSource = createDataTable();
            RadGrid1.AllowFilteringByColumn = true;
            

            RadGrid1.NeedDataSource += RadGrid1_NeedDataSource;
            RadGrid1.PreRender += RadGrid1_PreRender;
            RadGrid1.ItemCreated += RadGrid1_ItemCreated;

            //RadGrid1.DataBind();
            ScrPlaceHldr.Controls.Add(RadGrid1);
        }

        void RadGrid1_ItemCreated(object sender, GridItemEventArgs e)
        {
            if (e.Item is GridFilteringItem)
            {
                DateTime dtMinVal = new DateTime(0001, 01, 01, 00, 00, 00);
                DateTime dtMaxVal = new DateTime(9999, 12, 31, 23, 59, 59);

                GridFilteringItem fitem = (GridFilteringItem)e.Item;
                foreach (GridColumn col in RadGrid1.MasterTableView.RenderColumns)
                {
                    if (col.ColumnType == "GridDateTimeColumn")
                    {
                        RadDatePicker rp = (RadDatePicker)fitem[col.UniqueName].Controls[1];
                        RadDatePicker rp2 = (RadDatePicker)fitem[col.UniqueName].Controls[4];

                        if (null != rp)
                        {
                            rp.MinDate = dtMinVal;
                            rp.MaxDate = dtMaxVal;
                        }

                        if (null != rp2)
                        {
                            rp2.MinDate = dtMinVal;
                            rp2.MaxDate = dtMaxVal;
                        }
                    }
                }
            }

        }

        void RadGrid1_PreRender(object sender, EventArgs e)
        {
            //foreach (GridItem item in RadGrid1.MasterTableView.Items)
            //{
            //    if (item is GridEditableItem)
            //    {
            //        GridEditableItem editableItem = item as GridDataItem;
            //        editableItem.Edit = true;
            //    }
            //}

            //RadGrid1.Rebind();
        }

        void RadGrid1_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)
        {
            RadGrid1.DataSource = createDataTable();
        }

        void createColumn()
        {
            GridBoundColumn boundColumn;
            boundColumn = new GridBoundColumn();
            boundColumn.DataField = "Name";
            boundColumn.HeaderText = "Name";
            boundColumn.UniqueName = "Name";
            boundColumn.HeaderStyle.Width = Unit.Pixel(100);
            boundColumn.FilterControlWidth = Unit.Pixel(80);
            boundColumn.AllowFiltering = true;
            RadGrid1.MasterTableView.Columns.Add(boundColumn);
            

            DateTime dtMinVal = new DateTime(0001, 01, 01, 00, 00, 00);
            DateTime dtMaxVal = new DateTime(9999, 12, 31, 23, 59, 59);


            GridDateTimeColumn boundtimeColumn;
            boundtimeColumn = new GridDateTimeColumn();
            boundtimeColumn.DataField = "Date";
            boundtimeColumn.HeaderText = "Date";
            boundtimeColumn.UniqueName = "Date";
            boundtimeColumn.EnableRangeFiltering = true;
            boundtimeColumn.DataFormatString = "{0:dd/M/yyyy}";
            boundtimeColumn.HeaderStyle.Width = Unit.Pixel(100);
            boundtimeColumn.AllowFiltering = true;
            boundtimeColumn.MinDate = dtMinVal;
            boundtimeColumn.MaxDate = dtMaxVal;
            RadGrid1.MasterTableView.Columns.Add(boundtimeColumn);
        }

        private DataTable createDataTable()
        {
            DataTable dt = new DataTable();

            String strHeader = ("Name,Date");
            String strDataType = ("System.String,System.DateTime");
            String strData = ("Ram,01/05/2002 ,Ram1,01/05/2009,Ram2,01/09/2008");

            int nLength = strHeader.Split(',').Length - 1;
            int nLengthofData = strData.Split(',').Length - 1;
            String[] strHeaderArray = strHeader.Split(',');
            String[] strDataTypeArray = strDataType.Split(',');
            String[] strDataArray = strData.Split(',');


            for (int nStart = 0; nStart <= nLength; nStart++)
            {
                DataColumn columnString = new DataColumn(strHeaderArray[nStart]);
                columnString.DataType = System.Type.GetType(strDataTypeArray[nStart]);
                dt.Columns.Add(columnString);
            }


            for (int nDataStart = 0; nDataStart < nLengthofData; nDataStart = nDataStart + nLength + 1)
            {
                object[] array = new object[nLength + 1];

                for (int nStart = 0; nStart <= nLength; nStart++)
                {
                    array[nStart] = strDataArray[nDataStart + nStart];
                }

                dt.Rows.Add(array);

            }
            return dt;
        }

    }
}

here is the aspx file also

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
        <asp:PlaceHolder runat="server" ID="ScrPlaceHldr"></asp:PlaceHolder>
    </div>
    </form>
</body>
</html>

Regards,

Ramesh.

I now understand what you mean. The issue here is that you need to re-set the calendar range on the client as well. I created the following KB for you that demonstrates a solution: https://www.telerik.com/support/kb/aspnet-ajax/grid/details/extend-datetimecolumn-filter-range.

Based on you provided code, I also advise that you review the following article on properly binding the grid (said shorty, don't set its data source outside of the NeedDataSource handler, and don't call its .DataBind() method): https://www.telerik.com/support/kb/aspnet-ajax/grid/details/how-to-bind-radgrid-properly-on-server-side.

Hi Marin Bratanov,

Thank you for your prompted solution. It was nightmare for few days.!

Thanks again.

Regards,

Ramesh.