ajax calendar control inside a gridview inside a contentplac

Question

I have an ajax calendar control inside a gridview which is also inside a content place holder. The problem is that it gives me this output:

 

as you can see, I lost the Saturday ;( 

below is my code snippet

<asp:TemplateField HeaderText="Birthday">
                               <ItemTemplate>
                                   <ajaxToolkit:CalendarExtender ID="CalendarExtender3" runat="server"
                                       TargetControlID="txtFamilyDOB"
                                       CssClass="MyCalendarGv"
                                       Format="dd/MM/yyyy"
                                       BehaviorID="_content_CalendarExtender3"/>

                                       <asp:TextBox ID="txtFamilyDOB" runat="server" Style="padding:0; width:125px;" CssClass="form-control"></asp:TextBox>
                                   <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="txtFamilyDOB"
                                       ErrorMessage="*" SetFocusOnError="True" Font-Bold="true" ForeColor="Red"></asp:RequiredFieldValidator>
                               </ItemTemplate>
                               <ItemStyle Font-Size="7pt" />
                           </asp:TemplateField>

Below is my css

.MyCalendarGv .ajax__calendar_container{
            border: 1px solid #646464;
            background-color: lemonchiffon;
            color: red;
            font-size:small;
        }

Thanks for any help.