Agree that there is no set time but if you track weight and sheds in whatever method you choose, you can guess within a couple weeks usually. I track basically everything on reptilescan software and every single one of my animals usually go into shed reasonably close to when I predict. Lets say Snake A is 150 grams and shed again at 200 grams, I can kind of count on the next shed being around 260 or 270.
Mine all seen to gain a tad more between each shed than they did the shed before it. My 900 gram female shed two days ago after a 130 gram increase. Her next one will probably be in another 140 to 150 grams.
The smaller ones shed with far less weight gain between but it steadily goes up as they get bigger.
Now I only have 10 BP's but it just works that way with all of mine.