Brimfield Flea Market: Brimfield Auction Acres only field to open in May, all other fields commit to reopen in July, September Updated 3:08 PM; Facebook Share Typically, Brimfield Flea Market is busiest in May. This year, however, there will only be one field open. The Brimfield Auction Acres, also sometimes known as J&J, will be the only field to open during the show on May 11 through the 16, MassLive previously reported. The Brimfield Barn will also be open, although will operate differently than a normal show. In a press release from the Brimfield Show Promoters Association, 18 other field operators said they will not be opening in May. However, all field operators said they will be opening for the July and September shows.