Hi Curtis,
Thank you for your interest in Syncfusion product.
We have created the table with DateTime field column. In GridGroupingControl the DateTime Column has been showed with MonthCalender. In your previous update mentioned None button showed in MonthCalendar drop down. I cannot able to saw any None button in month calendar.
Please refer the sample in below link:
http://files.syncfusion.com/support/samples/Grid.Windows/Forums/GGCCell.zipLet me know if you still see the None button in month calender, it would be helpful more details about the issue.
Regards,
Lingaraj S.