Hi Linda,
Currently there is no way to programmatically unselect a cell in MonthCalendarAdv. There is an open Defect regarding this (
Defect #297).
However, there is a way to add this functionality yourself if you have a source subscription and are willing to modify the code yourself. If you''re interested in that, please create a Direct-Trac incident and I''ll explain how to go about it.
Regards,
Gregory Austin
Syncfusion Inc.
P.S. MonthCalendarAdv is a part of the Editor package of Tools, not Edit.