Fashion frenzy reaches a fever pitch when New York Fashion Week — that biannual style jamboree — sashays in Sept. 7-13. Runways all over town feature designers’ artistry and visions for spring/summer ’18 (along with some see-now-buy-now looks for instant gratification seekers). Off the runway, it’s all about people-watching, including a fair amount of celebrity-spotting. But there will be less time to watch and spot fashionistas and luminaries this season, as the newly streamlined schedule has one day lopped off at the end — the result, perhaps, of some major designer defections.

Bad news first: Tommy Hilfiger will show in London, and Thom Browne, Altuzarra and Lacoste have all said “oui,” to showing in Paris. They join Proenza Schouler, Rodarte and Monique Lhuillier, who have also moved their shows there.

That’s not to say that the schedule is without high drama. Notable: Master of swank Tom Ford will open the week at the Park Avenue Armory. And hail RiRi — Fenty Puma by Rihanna returns to the schedule with a late-night show Sept. 10, just a couple of days after the pop star introduces a beauty line.

Ralph Lauren is relocating his show to upstate Bedford, where guests — who’ve been asked to dress in formal black and white attire — will see his latest looks in a garage housing one of the world’s most expensive car collections (think vintage Ferraris, Bugattis and Bentleys).

Fashion Week’s last day is bookended by Michael Kors at the beginning and Marc Jacobs, who is always the closer. In between, there’s the couture chic of Delpozo, and the froth factor at Marchesa.

Many designers will strut their stuff at a fashion hub, either Skylight Clarkson Studio on Washington Street (where the Project Runway season 16 finale will be filmed) or Pier 59 at Chelsea Piers. Eva Longoria will debut her affordable, eponymous collection within the Kia STYLE 360 roster at Metropolitan West on 46th Street.

And there are plenty of off-the-beaten path show sites, as well. Carolina Herrera is tapping into the art world by hosting her nighttime spring show at The Museum of Modern Art’s sculpture garden. Tory Burch heads uptown to the Cooper Hewitt museum; Malan Breton will get fancy on the USS Intrepid; Sachin & Babi will raise the fashion bar at the New York City Bar Association; Adam Lippes will present at the New York Marble Cemetery; Kate Spade will shell out fashion at the Oyster Bar in Grand Central and the luxurious Oscar de la Renta collection will, swoon, show at Sotheby’s.

It certainly won’t be same-old, same-old at Cinq à Sept atop the Beekman Hotel, where a troupe of female performers — jugglers, ballerinas, contortionists — will perform wearing the brand’s clothes, amid the models.

For the brother-and-sister team behind the Nicholas K label, it’s off to Tulum, Mexico — virtually, that is — with an Instagram presentation in lieu of a runway show that was shot there in August.

Unanswered questions? There’s the perennial Kanye West query: Will he show his Adidas-affiliated Yeezy collection (it’s season 6) or will he pass? Stay tuned.