There is a little bit of an idea of how to use calendar keywords here;
http://docs.automic.com/documentation/AE/10.0/english/AE_WEBHELP/help.htm?product=awa#ucacnt.htmTo create a rule called WORKDAYS, you need the following;
(1) create one keyword for each of your holidays.
(2) create a group keyword called HOLIDAYS that includes all of your holidays.
(3) create a weekly keyword called WEEKDAYS that includes only those days that your business is usually open.
(4) create a group keyword called WORKDAYS that references WEEKDAYS and excludes HOLIDAYS.