So I got a call from a state librarian. She had a pamphlet from our city about a Lumberman Days event that had been held. It had the dates (October 17-20), but not the year. She had a guess as to what decades, but she really wanted a concrete decade, if not year.
Using our past year indexes (which are indexed by subject, and since this was held by a historical society, there was a subject for that), we were able to track down one of the years the event had been held (1976). From there, using the dates the event said, we knew that it wasn't the right year for this event.
So, using a perpetual calendar, we were able to find out what days those dates were. So Thurs-Sunday, and from there, we were able to pinpoint a year.
Once we had a year from the perpetual calendar (1974), we were able to go back to our indexes for 1974, go to the historical society subject and find the articles that pertained to the Lumberman Days. When we found the articles, we were able to confirm the dates, and therefore the year.
All in all, it took just over an hour, between helping other patrons, tracking down the info and using the indexes, which are paper. Our digital indexes don't start until 1994, although I'd really like to index the indexes.