You can sign up at fandango to get an email when tickets are available. The sale date hasn't been set yet.
Go to their website.
I suggest getting the CMX app and checking for ticket sales there. Then you could even pick your seats.
Probably 2-4 weeks before. Since the Chateau has recently changed to become a CMX, nothing has been consistent. Some movie tickets are for sale weeks ahead, and others only a few days. But Black Panther tickets were on sale about 4 weeks before.
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