Hi nityasri,
There might be problem in your javascript function to display date in "MMM dd" format.
You can use ajax control toolkit calendar extender to pick the date in your defined format.
Following is the sample aspx code for that.
<asp:TextBox ID="txtDate" runat="server" Width="200"></asp:TextBox>
<asp:Image ID="imgCalendar" runat="server" ImageUrl="~/Calendar_scheduleHS.png" />
<ajax:CalendarExtender ID="CE_txtDate" runat="server" Format="MMM dd" TargetControlID="txtDate" PopupButtonID="imgCalendar"></ajax:CalendarExtender>
You can change the format as per your requirement. Please feel free to ask, if i am not correct to your question.
Regards,
Manoj