The 'months' filter does not include all months spanned by events

[abea]

The months filter currently only returns the months of the event start dates. If events are only in one month this makes sense, but as event span more than one (or many) months, people will want to look for events in a particular month and find none, when an event actually does span that month.

So my event "Winter" has startDate of December 1, 2019 and endDate of March 1, 2020, but only December 2019 will be included in the months. People seeing if Winter is active in January will think it is not.