Add Close Button to DateTimeLocal TextBox in ASP.Net

Hello,

How to add close button to textmode datetimelocal in asp.net

I have created one asp:textbox with textmode=datetimelocal as shown below

It works fine but there is no close button so if user want to close calender and time pop-up he need to click outside.

Can we add close button to textbox so after selection of date and time, user can close the pop-up and proceed (selected value of date and time should not be cleared)

Thanks in advance

<asp:TextBox runat="server" CssClass="form-control" TextMode="DateTimeLocal" ID="txttimein"></asp:TextBox>