Here’s how these things work together: Someone searches “Georgia State University Homecoming Parade” in Google. If there aren’t any future events matching that search, past events will still appear in the search results, which will drive traffic to the calendar (increased SEO). Now since the past event is archived it was picked up by the search engine allowing a user to learn that there was a “Race for the Cure 5k” in October of 2019 so there could be one the next October. Both reasons go hand in hand. That being said, this does only apply to outside searches. If a user searches for a past event in the calendar search box next to the login links they will be met with a message stating that no events were found and with a prompt to “search past events.” 

For those using a search engine to find an event, they might not realize that the event has passed. Therefore, you can create a disclaimer – mentioning that this event has already happened. Please review the Uservoice article on how to create a past events disclaimer.