This feature is in development. We are aware of some shortcomings, and are in conversation with the service provider about resolving them. It is possible that this feature may be removed, or replaced with a similar feature from a different service provider.
On occasion somebody who organises an event or oversees an activity may forget to add an entry to the calendar, so don’t assume that something has been cancelled if you have seen it publicised elsewhere but it’s not on the calendar.