Supergirl opened in North American theaters on June 26. On September 10, it becomes an HBO Max title worldwide.

That is a 76-day gap.

The US linear HBO premiere follows two days later, on September 12 at 8 p.m. ET.

One movie, several commercial windows

Supergirl has already moved through the earlier stages of Warner's release pipeline. Theatrical exhibition came first, followed by transactional digital availability for viewers willing to buy or rent rather than wait.

HBO Max is the subscription stage.

The audiences for those windows overlap, but their economics are different. Early access extracts more revenue from viewers who value immediacy. Subscription streaming serves people willing to trade time for a lower marginal cost.

An underperforming theatrical run makes streaming more relevant

The movie's box office was below DC Studios' expectations. It debuted with roughly $62.6 million worldwide and ultimately finished around $126 million globally.

Peter Safran has publicly acknowledged the disappointment while maintaining confidence in DC's broader strategy.

HBO Max cannot retroactively turn those theatrical tickets into a hit. It can give the movie another job: driving viewing time, reinforcing DC's presence on the service and potentially helping subscription retention.

Those effects are harder to measure from outside Warner because streaming services disclose far less standardized performance data than theaters do.

HBO Max is becoming a natural home for the new DCU

Milly Alcock's Supergirl had already appeared in Superman before receiving her own movie. That connection makes HBO Max increasingly useful for viewers who want to follow the new shared universe without catching every film during its initial theatrical run.

Craig Gillespie's movie remains largely self-contained, sending Kara, Ruthye and Krypto on an interstellar pursuit of Krem of the Yellow Hills, with Jason Momoa making his DCU debut as Lobo.

The listed runtime can vary by home format

The BBFC classifies the theatrical 2D and IMAX versions at 107 minutes and 56 seconds. Its home-entertainment classification lists a 103-minute-and-17-second version.

Differences of this kind can result from frame-rate and master variations across theatrical and home formats rather than necessarily indicating several minutes of deleted story material.

The runtime displayed to viewers may therefore vary slightly by service and territory.

September 10 is the release date for everyone who chose to wait

Streaming does not give Supergirl a different script, a different theatrical result or a different place in the DC Universe.

It changes the barrier to entry.

For an existing HBO Max subscriber, Kara's latest trip across the galaxy becomes part of the monthly subscription on September 10.