That all depends on the snake, whether or not you put it through brumation or whether it chose to brumate itself. Usually around Spring time - April, May,. one of our male BPs brumates himself and goes off feed for around 6 months. He came back up in May last year. Others will come up sooner, or you can artificially provide a change in temps and light to increase the chances of your snake coming out of brumation sooner, although it's quite safe to leave them to it, just change waters weekly and check on them every couple of weeks.
I've just read your post again and I think you mean in the wild, not in captivity as I earlier suggested?.. again, they should come out around Spring time, as the temps start getting warmer and days start getting longer.
