I think the understanding used to be that the BPs had to go through a 'cooling' period to breed well. Some breeders do that, some do not. But if you were doing that, it's much easier to do so during the colder part of the year.

Otherwise, as long as you're controlling the environment, you can make it any time of year to the snakes. What you can't do is making a female ready to breed if her body isn't ready. So some people have asked me if they could make a BP double clutch(2 breedings in a single year) and I honestly think the answer is no. I think that BP females that have lain a clutch usually take some time to get back up to breeding readiness. Is that proven? Not really. Just my own personal opinion, although I haven't ever heard of any breeder getting a BP to double clutch on a regular basis(or actually... ever). I'm not talking about the technical of "Well, I bred this female really late, then bred her really early the next season so she technically bred twice in a calender year!". I'm talking about true double-clutching. Maybe it does happen and I'm the only person in the planet that doesn't know... shrug.

At any rate, after rambling on in tangents... yes, you can breed at any time of year as long as your snakes as healthy and ready to go.