Last fall, AEW filed a trademark for "Tuesday Night Dynamite", leading one to assume the company already had its desired night in mind. However, a report from PWInsider claims that on Tuesday, June 18, AEW filed a new trademark for "Wednesday Night Dynamite".
With WWE SmackDown Live moving to Fridays upon the show's switch to FOX in October, Tuesday nights were freed up for AEW to run without any direct competition, thus the idea of running Tuesdays made sense. However, with this latest trademark filing, coming roughly three months before the tentative launch, it seems like Wednesdays have been ultimately settled upon.
Neither the company nor WarnerMedia has issued a formal statement regarding the show's weekly air date. The only real information publicly offered at this point is that the show will be live from different venues each week, and a two-hour runtime.