Swimming lessons - is it normal to ay SO far in advance?

[loomer]

DD2 has been having group lessons for a few years now. We are very happy with the teachers, ratio of staff to kids etc. no reason to change, however in the latest email they have emphasised that they will expect payment IN FULL by the end of November for the Spring term. In the past they have always required payment in full in advance of the term beginning, but this is the first time that they have specified a date which is six weeks in advance. I understand that they have pool hire costs to cover as well as staff wages, but I can't think of any other industry where it would be acceptable to demand payment for a service in full six weeks before you even begin to provide it.
How far in advance are you expected to pay for swimming lessons?

We used to pay monthly by direct debit

We pay monthly. However, my DD’s ballet lessons are all paid up for the spring term as of about a month ago!

Ours is demanding payment now.

Ballet used to be horrendous - red warning letters and SHOUTY empty threats in if you hadn't coughed up by a week or so BEFORE half term. We ended up finding another ballet school.

Ours is 10 week terms and they take payment about halfway through a term for the next term. So payment for this current term was taken in June.

We pay for 10 week-ish blocks, they correspond roughly with school terms but not exactly. We've just paid up now for the Spring term block (if you're an existing pupil you can book up first to keep your place before they open to new bookings).