Apple TV Plus launches today, and Apple has a pretty slick limited time deal: buy a new iPhone, iPad, iPod touch, Apple TV, or Mac, and you’ll get a free one-year trial of the company’s fledgling streaming service.

But there’s a catch: claiming the free trial automatically signs you up for a monthly subscription that kicks in once the free trial ends, which will continue to automatically renew until you cancel it. Try to opt out of the auto-renewal, and your free trial will instantly end, with no way to get whatever months you have left of the free trial back.

Set a reminder now to cancel Apple TV Plus on October 31st, 2020

That means to make the most of your free year, you shouldn’t cancel the service until right before it ends. If you’re activating the free trial now, that means you’ll want to cancel no later than October 31st, 2020, to make sure that you get the full year without getting charged. (Apple says that customers have to cancel “at least a day before each renewal date.”)

In other words, if you’re giving Apple TV Plus a shot, make sure to set a reminder to cancel it in slightly less than a year from now, assuming you don’t want to keep paying.

Other useful things to know about the Apple TV Plus free trial: