I think, you can join anytime you want. Mind it, it depends in which month you are joining, because you will get the next season box anyway. If you join as I did, in July, your first box will be the fall box. Actually my opinion is that it's more worth to get the annual subscription because it's coming with a lot of perks. And, if you don't like the next, upcoming box, from the spoilers, you can skip that box and pick up with the next season. They have excellent sales with crazy low prices and the annual members have access to it first. So, it's up to you. Also, you can read up on this on their website and find whatever you want to know. Hope, this will help you.