*We do not have a function that access grant can be denied for a certain user on a irregular day.
We can grant/deny access to a certain user only on regular days basis (weekends, nationaly holidays).
1) You can set this from Settings -> Schedule
2) Then go on to "add schedule" to set the schedule you would like.
3) If you click on Holiday Schedule, you can set the regular holidays yourself.
In this way you can set the schedule and use it for Access Group.
4) Go to Access Control -> "Add Access Group" -> "+Add" button on Floor Level
5) In the "Add Floor Level" window, set the schedule as you wish.
In this way you can use your own schedule to setup access group.
Hope that was helpful.