I think they said this season will be short. Maybe 9 instead of 12.
It’s a regular 28 day / 12 war season. There are 21 days remaining.
It’s interesting because the solo event that gives crystals will still be running after banquet is over, some smaller alliances won’t reach it until the end.
My alliance is a 10 person alliance. Tried to get more, but it just didn't work out. Perhaps next year the alliance will be at 20 or even 30. I'm hoping at this point to at least get three of the four milestones, but will have to wait and see.