A fall season does not line up with a calendar year, which is why the application asks for a term length instead of assuming twelve months.
The 3-month term
Fits a tight operation: a patch that opens the weekend after Labor Day, closes on Halloween, and needs only a short window on either side for setup and cleanup. Roughly nine weeks of selling inside a twelve-week wrapper.
The 6-month term
Fits a longer run, or a business bridging two seasons. A patch that opens in early September, runs through the first weekend of November, then reopens the same ground as a Christmas tree lot in December often finds one 6-month term simpler than applying twice.
Count the weeks nobody counts
Most operators think of the season as opening day to closing day. The insurance question is different. Cutting maze paths, hauling in straw bales, setting fence line, and grading a parking field all happen before the first ticket is sold, and the equipment coming back out happens after the last one. That work is part of the operation.
What happens outside the term
Coverage applies during the policy period you select, not before it starts and not after it ends. If setup begins three weeks before your listed open date, the term needs to start early enough to include it.
Picking between them
Count backward from the last teardown day to the first setup day, add a buffer week on each end, then pick whichever term covers that span comfortably. The 6-month term costs more and removes the guesswork.