To add Work Calendar Exceptions for User :

From the main menu, click on and then Company Settings.
Under Company section, click on Work Calendars.
Navigate to the Exceptions tab.
Click Add.
From the For drop-down, select the user for whom you want to enter an exception.
In the Summary box, type the details of your event/exception.
From the Impacts Scheduling drop-down list select an option - Working / Non working.
From the date picker select a date. You can create the event for a whole day or for a specific time (un-check the All Day checkbox).
From the Repeat tab, select an appropriate option.
Click Submit. The exception is added.

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