For those who are interested, Governors Island National Monument has a number of special events during the season. It's unlikely I would run a tour during one of those weekends but they're a great time to visit to catch a living history event. Here are the weekends I know of:

June 21 - 22 Army Heritage

August 2-3 Revolutionary War

August 9-10 Civil War

August 23-24 Battle of Brooklyn

You can visit their website for more details on the island and these events (as they get closer). I've been on island for the Civil War event the past two years and it's fantastic. Link to some of my photos from the event.