Yet shows still matter to many designers. In an email, Brandon Maxwell, who dressed Lady Gaga, Melissa McCarthy and Sarah Paulson at the 2019 Oscars, said that “from a business and brand perspective NYFW is the priority, so we are focusing our efforts and resources there.” His show is scheduled the night before the awards.

At one point, the best way for designers to draw attention to a runway show was to put celebrities in their front row. This, too, has become difficult with the overlapping calendar, especially for labels whose shows are scheduled closest to the Oscars.

(The Badgley Mischka, show will end more than 24 hours before red carpet coverage begins, so the designers have it easier than others. Still, it is not ideal; because of the show’s proximity to the awards, its 2020 invite list focuses more on New York-based V.I.P.s than in years past.)

“I would be very concerned if I was one of those designers,” said Jessica Morgan of the celebrity fashion blog Go Fug Yourself, referring to the shows scheduled during the Oscars coverage. Ms. Morgan spent about a decade covering fashion week for New York magazine and Cosmopolitan. Awards season is her website’s biggest traffic period of the year.

“For one thing, you’re not going to have any celebrities there — maybe a few, but not anyone big,” she said. “And no big stylists are going to be able to attend their show because they’re going to be putting clients in Oscar or Vanity Fair Oscar party outfits.”

One designer scheduled for Sunday evening is Jason Wu, a celebrity favorite. (Mr. Wu declined to comment for this article.) Otherwise, the CFDA appears to have worked around fashion week’s big names. Prabal Gurung has shown on Sunday evening for the last four seasons; this year, he has been moved to Tuesday evening.