Note: The Holiday framework is a technology preview.
Despite its age, is still draft API, and clients should treat it as such.
DateRule is an interface for calculating the date of an event.
It supports both recurring events and those which occur only once.
DateRule is useful for storing information about holidays,
Daylight Savings Time rules, and other events such as meetings.
Checks whether this event occurs on the given date. This does
not take time of day into account; instead it checks
whether this event and the given date are on the same day.
This is useful for applications such as determining whether a given
day is a holiday.