Editing Grid View row with HTML Input control - html

Question

I use a Grid view for show and edit data. A column represent birthday. As I need date picker for this field, I have used a HTML input control. The date picker is working charm but problem is I don't know how to save edited birthday field after editing. What should I write instead of this:
<ItemTemplate><input type="text" id="sabzlearn" class="TextBox" name="SimpleUserBirthdayTxt"/>
</ItemTemplate>
.Here is Grid view:
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSource1"
BackColor="#DEBA84" BorderColor="#DEBA84" BorderStyle="None" BorderWidth="1px" CellPadding="3" CellSpacing="2" OnRowEditing="GridView1_RowEditing">
<Columns>
<asp:CommandField ButtonType="Image" CancelText="Cancel" EditImageUrl="~/Images/editbutton.png" ShowEditButton="True" UpdateText="Change" ControlStyle-CssClass="GridViewSelect" />
<asp:BoundField DataField="FirstName" HeaderText="Name" SortExpression="FirstName" ControlStyle-CssClass="GridViewTextBox" />
<asp:BoundField DataField="LastName" HeaderText="SurName" SortExpression="LastName" ControlStyle-CssClass="GridViewTextBox" />
<asp:TemplateField HeaderText="Gender" SortExpression="Gender">
<EditItemTemplate>
<asp:DropDownList ID="DropDownList1" runat="server" SelectedValue='<%# Bind("Gender") %>' Width="50px">
<asp:ListItem>Male</asp:ListItem>
<asp:ListItem>Female</asp:ListItem>
</asp:DropDownList>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Bind("Gender") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Birthday">
<EditItemTemplate>
<input type="text" id="sabzlearn" class="TextBox" name="SimpleUserBirthdayTxt" value="<%#Eval("Birthday") %>"/>
<script type="text/javascript" src="../assets/js/jquery.js"></script>
<script type="text/javascript" src="../assets/js/kamadatepicker.min.js"></script>
<script type="text/javascript">
let options = {
placeholder: "DateHolder",
twodigit: false,
closeAfterSelect: true,
nextButtonIcon: "./assets/image/timeir_next.png",
previousButtonIcon: "./assets/image/timeir_prev.png",
buttonsColor: "red",
forceFarsiDigits: true,
markToday: true,
markHolidays: true,
highlightSelectedDay: true,
sync: true,
gotoToday: true,
}
kamaDatepicker("sabzlearn", options);
</script>
</EditItemTemplate>
<ItemTemplate>
<input type="text" id="sabzlearn" class="TextBox" name="SimpleUserBirthdayTxt"/>
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="Password" HeaderText="Password" SortExpression="Password" ControlStyle-CssClass="GridViewTextBox"/>
</Columns>
<FooterStyle BackColor="#F7DFB5" ForeColor="#8C4510" />
<HeaderStyle BackColor="#6699ff" Font-Bold="True" ForeColor="Black" />
<PagerStyle ForeColor="#8C4510" HorizontalAlign="Center" />
<RowStyle BackColor="#FFF7E7" ForeColor="#8C4510" />
<SelectedRowStyle BackColor="#738A9C" Font-Bold="True" ForeColor="White" />
<SortedAscendingCellStyle BackColor="#FFF1D4" />
<SortedAscendingHeaderStyle BackColor="#B95C30" />
<SortedDescendingCellStyle BackColor="#F1E5CE" />
<SortedDescendingHeaderStyle BackColor="#93451F" />
</asp:GridView>