Attention, future Oscar hopefuls: The Jan. 15 nominations are a reminder that the Venice-Telluride-Toronto festivals are no longer just a showcase — they’re a deadline.

For decades, Hollywood opened its prestige films in December.

For the films of 2002 — the year “Chicago” won — all five best-picture contenders had opened in December. That changed when Oscars switched dates, starting with the Feb. 29, 2004, telecast (saluting the films of 2003). Now, that 5-out-of-5 batting average has changed to two in eight.

Even so-called Oscar bellwethers no longer apply. Before the date change, the Golden Globe winner (either drama or comedy musical) was the same as Oscar in 17 of 20 years. Since then, it’s four of 11.

Voting results are secret, so it’s impossible to pinpoint reasons for the difference. This year’s big December openers included “Into the Woods,” “Selma” and “Unbroken.” Collectively, they gathered eight nominations — not bad, not great. The notable exception was “American Sniper,” with six noms, including best picture. Could it have earned more if it started screening earlier? We’ll never know.

Earning zero noms for their December Oscar-qualifying runs: “A Most Violent Year,” “Cake,” “Black or White,” “The Humbling” and “The Gambler.”

The big shift might be due to the films themselves. But Academy members vote only for what they’ve seen. Awards strategists had set up plentiful screenings for their late entries, but sometimes didn’t have the film in time.

And by Thanksgiving, buzz was already loud on films like “The Grand Budapest Hotel” (which opened in March), “Boyhood” (July) and others that had made the festival circuit. Of the 10 films that earned four or more nominations, most had premiered at a festival many months earlier.

Hollywood’s priority is always the bottom line, and the year-end holidays are important for box office. And there’s sometimes a conflict between the filmmakers’ delivery date and the accelerated Academy Awards.

But there’s no denying the date change has altered Oscar’s DNA.