A lot of closing dates are weather and tourist volume related. If the crowds are there and the weather is good they stay open longer. The posting of closures usually begins in July. You can expect upstairs at Leverick to be closed in early August. Chez Bamboo as well about the same time. September is the slowest month with a lot of business owners and staff on vacation. Mid October they start to open and by Nov 1 most are up and running for the season.
When we first started going in the early 80's most places were open year round.