Recently got back to playing a bit more, but there isn't a very clear pattern of the when the kataclysm arrives, and how long it is here for.
AFAIK it seems to have a 6 months in between, and twice a year.. although with the exception of 2015.
Maybe we can ask the people in charge for an early kataclysm during July / August? It is the summer break after all
PS. quick question, is it possible to feed your Book of Dark Rituals to a sprite? does it give more heat than normal 5* mats? Not that i'm gonna do it.
I doubt they'll announce the date of any event in advance.
I think if it is possible to feed the book to sprites, I assume it'd still give the same amount of heat as any regular 5* mat. After lvl 15 fav food is still the best, so no need to bother with it anyways.