Depending on the negotiating power of the studio, that may even extend to the second week for a major blockbuster film, like for example a Fast and Furious or Marvel film.

Generally, the studio's share of ticket sales drops below 50% after about a month. By the end of the second month, if the theater is still showing a movie, it is getting almost all of the ticket sales revenue.

This is why movie studios really push the concessions: that's where they make the most money. By the time they're making the lion's share of a movie ticket sale, there generally aren't many people still interested in watching the movie in a theater, so it's only worth it to keep long-tail movies in theaters for more than a few weeks.