when will the new championship start

one week after the current one finishes…

Taken directly from Ed Collins' great LittleGolem FAQ :

Championship Tournaments begin approximately ten days after the final game has been played in the previous Championship.

So, the answer is, expect the next chamionship to begin in about 7 to 10 days.

I think the 'current' one finished Wednesday. And my experiecnce is that the new one still usually starts closer to the 7 days it's supposed to be than a full 10 days. My guess is we'll be playing by Thursday.