MAC CALENDAR SEARCH NOT WORKING

I had this problem after re-indexing Spotlight (file content searches were not working) and applying an upgrade - they weren't done together, I'm just not sure when the problem started. I discovered that a calendar entry added after the upgrade could be found using a search. So I exported the calendar, deleted my calendar, and imported it. Searches now working. To avoid duplicate entries on my iPhone I deleted my calendar there, then synced.

My calendar search will only find events in the future, not the past. If I search on my phone, it finds the historical matches.