If you mark staff as unavailable in their Work Preferences calendar in OnCall, you can display those days in an Amion report.
Open your scheduler and go to File → Preferences and choose Amion Options in the upper left. Turn on the option to Show unavail. days in the "Who's away" list.
Publish your schedule to update the Amion server. At Amion go to the palm-tree report in your online schedule.
Unavailable days are flagged in maroon in the month-long graphic to the right of each name.
The list is broken into three sections. The top section shows people who are on vacation, at a CME, or assigned to some other service. The middle section shows who's asked to be unavailable for that day. The bottom section shows people who are marked as away or unavailable for some day of the month but not the selected day.
The current day is the default when you go to the palm-tree report but you can choose a different date with the dropdown selectors at the top. Click Go to move to another day.