The Validity and Exceptions setting of recurrence rule used is specified in the Validity and Exceptions panel of the recurrence rules tab control.
The Validity and Exceptions settings specify a variety of exceptional behavior for the current recurring holiday.
Set the Validity of recurring holidays to indicated the range of years to which the rule applies.
By default, each recurring holiday is created with its validity set to Always, meaning that the rule is valid for all years.
You can set the validity to Beginning or Ending, in case of a new holiday or a holiday being dropped on a given year. Set the validity to From/To if a given holiday rule is only valid for a range of years. Set the validity to Except, to indicate that a holiday rule will not be applied for a year or a range of years (for example, in the UK in 2002, the Late Spring Holiday was replaced by the Queen's Golden Jubilee).
In principle, any holiday based on a lunar or lunisolar calendar, could be concerned by this restriction. But, most lunisolar calendars have a method of compensating these double occurrences, except for the Muslim calendar. Therefore, in practice this restriction is only applied to Muslim holidays, and in particular for Christmas Island and the Cocos (Keeling) Islands.
This setting is used for many countries in Latin America and Asia where the date of some elections and presidential inaugurations is recurring, predictable, and is a public holiday, as well as in the Netherlands where May 5 is a public holiday for the private sector only every 5 years.
Exception to rules allow you to use recurrence rules, and to specify the years for which the rule does not apply. Note that in these cases, you could also use the arbitrary dates type of recurrence, but that would deprive you of the power of recurrence rules most of the time just because a few years do not fit the rule.
There are 2 types of exceptions.
Occurrences of this holiday that do not follow the rule
The presence of any exception date, for a given year, means that the rule for the current holiday of the current year is totally ignored and only the dates specified in the list of exceptions are counted.
This means that you need to add both the normal date and the additional date in the list of exceptions, in cases when a second day is added to a recurring holiday that usually lasts only one day. You cannot just add the additional date.
Years when this holiday does not occur at all
The second type of exception is when a holiday that usually occurs every year, does not occur at all for a given year.
For example, the Spring Bank Holiday in the UK was skipped in 2012 to be replaced, that year only, by the Queen's Diamond Jubilee.
If you specify that a holiday has no occurrence for a given year, but you have also specified exception dates for that same year and holiday, then a message informs you that if you continue, this will remove all dates which correspond to that year from the list of exception dates.