Update: The text below was updated with what we learned from speaking with representatives at HBO Max and Warner Bros.
The exact release date of Zack Snyder's Justice League will be a four-part TV series. Unfortunately, Snyder didn't divulge when it will officially roll out on the streaming platform next year.
It's been more than three months since the project was announced by Snyder himself after hosting a watch party for Justice League Snyder Cut's trailer debut, there's more interest in wanting to know when the public can get the full thing.
While Snyder didn't say anything specific about his Justice League's release date during DC FanDome, it may have inadvertently been leaked on a DC Press Portal website... A title page reveals the project will roll out on September 5, 2021 according to this , although when it'll be available on planes is unknown.
They claim this screenshot was taken from the official DC Press Portal website that we used ourselves during DC FanDome but when we checked hours after this tweet, this image did not match what was there. We reached out to Warner Bros. and HBO Max who confirm the date is not accurate.
We also asked if it was a placeholder date that could have been changed (specifically, if they swapped the attached Fact Sheet to the Zack Snyder's Justice League page) during those hours and did not receive a response. We've followed up again and will update according.
Either way this doesn't mean September 5, 2021 is a confirmed release date for Zack Snyder's Justice League. The date used is likely temporary one, since it doesn't seem like it was supposed to be ed to the site. Another possibility is Warner Bros. simply considering this date for the project. Depending on how things pan out in the next few months, especially regarding the ongoing coronavirus pandemic, they company may want to roll the Snyder Cut out earlier. In any case, it's best not to get too attached to this supposed release date for now; waiting for an official press release would be wiser.
If this is indeed the release date for Zack Snyder's Justice League, it's actually a good date for the film. September 5, 2021 is a Sunday. Typically, high profile projects drop on streaming services Friday so people can enjoy it on the weekend. However, since September 6 is a holiday (U.S. Labor Day), fans would have more time to enjoy it during the long weekend. Studios usually take advantage of this and roll out big films in theaters. HBO Max and DC may be using the same strategy here, which makes a lot of sense.
Sources: DC Entertainment, HBO Max