Schedules having duration types with mapping to the calendar (Week and Days/Weeks) may have exceptions - particular time intervals when the value defined by this schedule should have other values, differing from the ones defined in the schedule.
Schedule may have unlimited number of exceptions.
Exceptional intervals may have any duration - e.g. a half an hour in some particular day, or the whole day of the year (or even several days in succession).
Exceptions are defined in the Exceptions section of the Properties view of the schedule. In general you will need to define both start and end dates and times for each particular interval. But since frequently exceptions are exactly one day-long, AnyLogic supports special simplified definition mode for this case, named All day. In this mode you only specify particular days you want to make exceptions but do not have to define start and end times for each exceptional interval.
The most frequent use case of "all day" exceptions are national holidays. In case your schedule defines a work timetable for some resources and you want to consider day offs caused by national holidays, you can declare holidays as exceptions and set zero value or off status (depending on the schedule's Type) for them. This will lead to considering these days as days off further to regular day offs.
Below you can see an example. Please note that the checkbox Annually is selected in all table rows since all these holidays are celebrated annually and there is no need to specify them separately for each year you plan to simulate.
Other frequently met case - workday transfers caused by national holidays. There are some countries (Russia, Ukraine, etc.) where workdays are transferred to days off. For instance, when a holiday falls on Tuesday, a day off is transferred from Saturday to Monday so that citizens will have three days off (Su Mo Tu) in succession. To define workday transfers, you need to declare the days off that will become workdays as the exceptions and set a non-zero value or on status (depending on the schedule's Type) for them.
You can see the following workday transfer defined in the given example. In 2013 the Victory Day is celebrated on Thursday, May, 9. So, the day off is transferred from Sunday, May, 12 to Friday, May, 10.
Let's assume that this schedule defines that some resources work regularly from 10 AM till 6 PM. As you can see, we have defined those particular intervals for the day off that was made the workday due to transfers.
Please note that the checkbox Annually is cleared since the transfer pattern is specific for each particular year.
Other use cases
You can also use exceptions for modeling less trivial tasks like the demand boost in the New Year's and Christmas Eve, or extension of the shop staff in those days.
To define exceptions for a schedule
Schedule with N Days/Weeks duration
Schedule with no calendar mapping