Multi-session events do not show up in the API when filtering by date unless the date filter range includes ALL the dates of ALL the sessions (not just the first one, I just verified this).

This IS INSANE. It makes the API completely useless for query events for a given date range without querying ALL events for a large timespan to figure out which ones might have a session on the selected days.

Does WA really want us regularly issuing queries that can potentially return thousands of events? For example, to list all events or sessions for a specific date we have to retrieve ALL events for at least a year before the date in question, to be sure of capturing an event that might have a session scheduled for that date.

To make things even more difficult, the queried date range must include ALL the session dates, not just the first date, so now we have to also query at least a year into the future as well.

It is clear that internally this information is available, given that the calendar has no problem listing event sessions. I'd be surprised if internally the code has to examine all prior and future events just to find sessions in the displayed month.

The API needs to be able to intelligently handle queries by date range and include all events that have sessions in the specified filter range, without the client having to query and then locally filter a much larger date range.