Defines a <a class="localLink" href="/Date">Date</a> or <a class="localLink" href="/DateTime">DateTime</a> during which a scheduled <a class="localLink" href="/Event">Event</a> will not take place. The property allows exceptions to
a <a class="localLink" href="/Schedule">Schedule</a> to be specified. If an exception is specified as a <a class="localLink" href="/DateTime">DateTime</a> then only the event that would have started at that specific date and time
should be excluded from the schedule. If an exception is specified as a <a class="localLink" href="/Date">Date</a> then any event that is scheduled for that 24 hour period should be
excluded from the schedule. This allows a whole day to be excluded from the schedule without having to itemise every scheduled event.