Still haven’t seen “Barbie” or “Oppenheimer?” On Sunday, you’ll be able to catch up for $4 a ticket in movie theaters around Chicago and nationwide.

For one day, all movies — in all formats and at all showtimes — will be $4 at participating theaters during the second annual National Cinema Day promotion.

Most theaters in the United States are taking part — more than 3,000 altogether, including leading chains AMC and Regal.

They’ll use the promotion to give audiences a peek of anticipated fall releases before each screening.

It’s the second year theaters are trotting out the one-day event at the tail end of summer. Last year’s inaugural National Cinema Day, put on by the Cinema Foundation, a nonprofit affiliate of the National Association of Theater Owners, attracted an estimated 8.1 million moviegoers last Sept. 3, when tickets were $1 cheaper at $3 apiece.

According to the theater owners group, a ticket to see a movie last year cost an average of $10.53.

The discount gimmick turned into the best-attended day of the year for theaters. A normally quiet time instead saw cinemas crowded with moviegoers — and theaters sold plenty of popcorn. This year, the day is shifting from a Saturday to a Sunday.

Thanks to remarkably sustained interest in “Barbie” and also “Oppenheimer,” August’s box office has been booming, with summer movie ticket sales up to $3.8 billion, according to data firm Comscore — about 16.6% ahead of 2022 at the same point.