Jay and Sofia Lyons set a date to mate.

Scheduling sex, designating a few days each week to do the do. It’s served as the “glue” that’s kept the Upper West Side couple happily hitched for over 31 years.

“It’s made our relationship one million times better,” Jay, an Emmy-winning director and producer, told The Post. “It’s the glue that keeps your marriage close — it’s very difficult to have a bad marriage when you’re regularly having sex.”

He and Sofia, both in their early 50s, began scheduling shags shortly after tying the knot and welcoming two kids in the early 1990s.

The pair is among the 14% of husbands and wives whose sex lives thrive on a regimen, per recent findings via virtual wedding hub The Knot. Jenna Bush Hager recently admitted to penciling in the deed and Amy Schumer said she does the same. Meanwhile, Nick and Vanessa Lachey picked “Wednesday — hump day” as their romp ritual.

“It makes your spouse feel appreciated and special,” said Sofia, a professional singer, adding that she likes leaving cutesy Post-it note reminders and risqué coupons for Jay ahead of their spicy rendezvous.

“It might sound silly,” she conceded, “but if something is special to you, you schedule it.”

And while penciling in hanky-panky might seem unsexy, lacking spiciness and spontaneity, Virgina Sadock, director of the human sexuality program at NYU Langone Health, assures that it’s not.

“Spontaneity is not the only way to have good sex,” Sadock told The Post, noting that those hot-to-trot impromptu romps in R-rated rom-coms are rare in reality — especially for duos with demanding careers, children or elderly parents.

“Most couples very often schedule sex — whether they know it or not,” she added.

It’s counting down until the kids are out at a sleepover or busy season at work finally ends.

Unmarried sweethearts even preplan their XXX playdates. Some set their watches for that all-important “third date,” while others book beauty and grooming appointments timed to the next time they expect to hook up with their honeys.

But putting coitus on a calendar isn’t a cry for relationship help, says Sadock, a clinical professor of psychiatry.

Instead, it’s relationship maintenance.

“After the honeymoon phase, couples go from falling in love, a euphoric experience, to being in love, when real-life sets in and passion subsides,” she said. “Setting dates for sex, scheduling date nights, kissing, touching and talking keeps the passion alive.”

Jackie Gibson, a mom of four kids under age 6, agrees. For her and her husband Seth, planning lovemaking has been a “game changer.”

“We have never been more in love or on fire for each other,” Jackie, 32, a lifestyle influencer from Dallas, Texas, tells The Post.

Ensuring sex is routinely on the agenda became crucial for the lovebirds of nearly a decade, after building their brood dampened the mood.

“In the beginning of our marriage, I was the one with the higher sex drive,” said Jackie, admitting that her libido has since ebbed and flowed due to postpartum following her pregnancies. “But scheduling sex adds this flirty energy to the day — it creates a fun mindset shift.”

She and Seth map out their saucy sessions on a physical calendar hanging in their shared home office. The twosome inks mini hearts in the corners of their Do-it dates.

Seth also sets phone notifications for himself that read “Love my wife,” revving up his engine for the erotic occasion, which happens about every four days.

“I used to be disgusted at the thought of scheduling intimacy,” Jackie admitted. “But as busy parents, we’re on a time crunch and we gotta make it happen to stay connected.”

“It’s not always this dreamy, romantic scenario,” she said, “but it’s always amazing.”

Hannah Deindorfer, 32, and fiancé Taylor, 38, keep things dreamy and steamy by sending naughty Google Calendar invitations to one another.

“We have King or Queen nights,” Hannah, a sex coach in Austin, told The Post.

“They’re planned, intentional evenings, when one of us gets to be pampered fully by whoever issued the invite.”

The twosome, both entrepreneurs working over 60 hours per week, are prepping to wed in June. They’ve scheduled sex since the onset of their romance three years ago.

But nowadays, their intercourse itinerary really comes in handy.

“The season of life that we’re in is incredibly busy so imperative to have this system in place,” said Hannah.

She swears prearranging sex isn’t as sterile as scheduling a doctor’s visit or a root canal.

“It’s an invite to a two-person party,” she raved. “We’re gonna have fun and make it special.”

“Anyone hating on this probably isn’t having the best sex.”