You can manually enter day off and other special requests in a special table view of work requests.
Right click on the Work Preferences icon (looks like a little face underneath the word 'View' on the task bar); and select Table as your default view.
To enter requests in the table, select an option from the off schedule option box:
Once you've selected your assignment (i.e. sick, vacation, CME, etc) from the drop-down menu, double-click (followed by a single-click for subsequent days) on a date in the special requests table to enter requests for each person. To return to your main working view, click on either the Table or Calendar icon located in the upper left corner of your screen.