His daughter, Laurie Newbound, said through a spokeswoman that the cause was complications of Lewy body dementia.

Slade was a stage actor and theatrical producer before he turned his attention to writing. After substantial success in Canada, he signed a contract with Screen Gems to write three television pilots a year.

With Harry Ackerman he created “Love on a Rooftop,” a romantic comedy seen on ABC in the 1966-67 season. He fared somewhat better as a creator of “The Flying Nun,” which premiered in 1967 and ran for three seasons, advancing the career of its young star, Sally Field.

“The Partridge Family,” a comedy about a musical family that finds success as a pop band, made its debut in September 1970, with Shirley Jones as the matriarch and David Cassidy playing the resident heartthrob.

“While in Canada I had written a television play called ‘The Big Coin Sound,’ which was about a vocal group,” Slade recalled in his memoir, “Shared Laughter” (2000). “Then one night I happened to catch a family group called the Cowsills on ‘The Tonight Show.’ Since ‘The Sound of Music’ was enormously popular at the time, I thought the combination of original music and comedy could be very effective in a television series.”

The producers originally thought of casting some members of the Cowsills, but, as Slade put it, they “didn’t really fit into any of the characters that I had written,” and so Jones, Cassidy, Susan Dey, Danny Bonaduce and others were cast as Partridges. The resulting show ran for four seasons on ABC, made a teenage idol out of Cassidy, spawned hit records and became a touchstone of 1970s kitsch.

Slade wrote a number of the show’s 96 episodes, but by the end of its run he had become disenchanted with television and had turned his attention back to his original interest, theater. In 1975 he found spectacular success with “Same Time, Next Year,” a two-hander about a man and a woman, each married to someone else, who are having a very particular type of affair, meeting just once a year at the same inn.

The play, with Ellen Burstyn and Charles Grodin constituting the opening-night cast and Gene Saks directing, ran for almost 3 1/2 years. Clive Barnes, reviewing the premiere in The New York Times, was ecstatic.

“It is a delicious and very moral kind of immoral play,” he wrote. “It has wit, compassion, a sense of humor and a feel for nostalgia — who could ask for anything more? It restores one’s faith in the possibility of a commercially styled Broadway hit — for here is a play clearly geared for popularity that does not for one moment talk down to its audience.”

Slade’s first Broadway credit, it was nominated for a Tony Award for best play.

“Same Time, Next Year,” which ran for 1,453 performances on Broadway and had name actors replacing the original stars over the years, became a staple of theaters large and small and is often described as one of the most-produced plays in the world. Slade adapted it into a 1978 movie, which starred Burstyn and Alan Alda. It was nominated for four Oscars.

Part of the appeal of the play is that Slade made it more than merely a gentle romance. As its characters meet year after year, they change in ways that reflect the changing times.

“What puts the final icing on Mr. Slade’s wonderfully confectioned cake,” Barnes wrote, “is the way in which he contrives to give us a social history of the United States during the past quarter‐century. His eye and ear for salient detail are sure, and the period feel is assisted by the evocative use of nostalgic tapes (speeches, songs, sports broadcasts of the period) between the scenes. Clever, clever, Mr. Slade.”

Bernard Slade Newbound was born on May 2, 1930, in St. Catharines, Ontario, about 13 miles from Niagara Falls. His parents, Frederick and Bessie Newbound, were British, and in 1935 they returned to England. During World War II, the family moved around constantly because of wartime evacuations; young Bernard attended 13 schools in seven years.

At 18 he returned to Canada, settling in Toronto and taking a job “working in a customs cage stamping little cards that came out of nowhere and went he knew not whither,” as Macleans magazine put it in 1975. He answered an ad for summer-stock actors, leading to numerous roles onstage and on television and radio in Canada.

In 1953 he married Jill Foster, an actress who had responded to that same summer-stock ad, and they ran a theater in Vineland, Ontario, for a time.

Slade’s writing credits in the early 1960s included several installments of the Canadian anthology series “Playdate” and “Encounter.” In 1964 he relocated to Los Angeles. In addition to his early breakthrough, “Love on a Rooftop,” he wrote 17 episodes of the popular comedy “Bewitched” in the mid-1960s. In the early 1970s he created and wrote episodes of “The Girl With Something Extra,” which also starred Field, and “Bridget Loves Bernie.”

In David Cassidy’s autobiography, “Could It Be Forever? My Story” (2007), Slade is quoted explaining the origin of the family name in his best-known TV show.

“The show was originally called ‘The Family Business’ and later changed to ‘The Partridge Family,’” he said. “I went to school in England and played on the soccer team. The center-half was a guy named Partridge, which, as it turned out, was not that uncommon a name. But at the time I thought it was unusual and it seemed fitting.”

Slade began writing “Same Time, Next Year” while waiting in an airport, sketching out the first scene on airline stationery. He wrote many other plays as well. One of them, “Tribute,” about a man who learns he has leukemia, opened on Broadway in June 1978. It starred Jack Lemmon and ran for 212 performances. Lemmon also starred in a 1980 film version.

Slade had another Broadway success with “Romantic Comedy,” which opened in October 1979 with Mia Farrow and Anthony Perkins leading the cast.

“Writing for theater is very public,” Slade told The Times as that play was getting ready to open. “You put it on the line each time. Elsewhere you’re as good as your best play, but in America you seem to be only as good as your last.”

“Romantic Comedy” ran for almost a year, but Slade’s last Broadway effort, “Special Occasions” in 1982, was a flop. It starred Richard Mulligan and Suzanne Pleshette, who was then well known from the popular 1970s TV series “The Bob Newhart Show.”

“It’s not nearly as amusing as ‘The Bob Newhart Show,’ ” Frank Rich wrote in The Times, “it’s just longer and more sparsely populated.”

It closed after the opening-night performance.

Slade’s wife died in 2017. In addition to his daughter, he is survived by a sister, Shirley Rabone; a son, Chris Newbound; and four granddaughters.

In 1975, as he was transitioning out of TV writing, Slade acknowledged having some trepidation early in his career about the types of things he was writing.

“The closest I came to being embarrassed is when I wouldn’t tell people the title of what I was working on,” the Macleans article quoted him as saying. “I was ducking into doorways when I’d see friends. I mean, I did not want as an epitaph, ‘He Created The Flying Nun.’ ”

This article originally appeared in

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