Over the past few years, China has grown to become the second largest box office market in the world, behind the U.S., with Chinese grosses often saving some movies from the brink of total failure. With the summer movie season in full swing, a new report reveals that there has yet to be a release date announced in China for last weekend's box office winner, Spider-Man: Homecoming, this week's War For the Planet of the Apes and next week's Valerian and the City of a Thousand Planets. It is believed that none of these movies will open until August, at the earliest, hinting that China is enlisting its infamous Hollywood summer blackout once again.

The Hollywood Reporter reveals that another upcoming release, Warner Bros.' World War II epic Dunkirk won't be released in China until September 1, long after it opens in the U.S. on July 21. Most of Hollywood's big-budget tentpoles this year have opened day-and-date with China, or just a few days after its North American debut, and later release dates have been known to diminish box office results significantly, especially due to the ongoing threat of piracy. China has long enacted a "Hollywood blackout" during its summer months, but many industry insiders thought that would be abandoned after last year.

RELATED: Spider-Man: Homecoming Star Was Convinced Zendaya Had Stolen Her Role

The Chinese summer blackout, known in the country as their "domestic movie protection period," was designed to give Chinese films a chance to flourish on their own through the country's summer school break, which runs from late June through August. There are also brief blackouts during the Chinese New Year in February and the Golden Week holiday in October. The 2015 blackout lasted from June 19 through August 23, which paved the way for the Chinese hit Monster Hunt to become the biggest movie in Chinese box office history ($385.2 million), while other local hits like Monkey King and Pancake Man earned over $150 million each. But last year, the blackout was lifted much earlier, due to a spate of underperforming movies, which allowed U.S. summer movies like The Legend of Tarzan, Teenage Mutant Ninja Turtles: Out of the Shadows, The Secret Life of Pets and Jason Bourne to be released in Chinese theaters. Some box office analysts thought the blackout lift last year could signal that the practice would be abolished, but it seems that is not the case.

A report from May revealed that trade officials from both Beijing and Washington D.C. are renegotiating terms of Hollywood doing business with China, which is why many insiders thought that the summer blackout would not happen this year. The Chinese government uses these blackouts, along with other means like quotas and reduced revenue shares, to try and maintain a 55% market share for Chinese movies at the national box office, although they still want to keep their growth at a rate where they will eventually overtake the U.S. as the number 1 market in the world. Accounting firm PricewaterhouseCoopers projects that may happen by the year 2020.

This report also reveals that Chinese movies are continuing to underperform, which lead to Chinese regulators allowing 57 Hollywood movies into the country during the first half of 2017, 14 more movies that were allowed last year. This has caused the Chinese market share to drop down to 39%, which is most likely why this blackout is being reinstated. If films like Spider-Man: Homecoming is given a delayed release in China, it could prove to be quite costly. For example, Marvel's Guardians of the Galaxy Vol. 2 is winding down its theatrical run, taking in $385.6 million domestic and $472.5 million coming from international markets. Of that foreign tally, China has by far the biggest share, pulling in $100.6 million, or roughly 21% of its full foreign take. That movie opened on the same date in China as it did in the U.S., but if the China debut for Spidey is significantly delayed, then it may prove to be quite costly in the long run for Marvel.