Still possible to join 90 day challenge?

I joined lingq after the challenge started, but I noticed on the homepage there is still a link to join the challenge. Is it still possible to join even though it already started? I’m enjoying lingq as it is, but also like having a bit of structure and goals and it seems that the challenge provides a bit of that from what I have read.

Why not start now, and keep going to see what you can achieve in 90 days. I certainly have made more progress in the last 25 days in Korean, than at any similar period before. Just step up the tempo!