"Like sands through the hourglass, so are the days of our lives. This is Macdonald Carey and these are the Days of Our Lives."

These are the opening lines that have been intoned by former Broadway and screen star Macdonald Carey, playing Dr. Tom Horton Sr., five days weekly since Nov. 8, 1965.

Unlike movies and prime-time TV, where preference is given to the young and beautiful, daytime programming has provided a haven for over-50 actors. They are, in fact, essential: Almost every show is built around the "core" family or "tentpoles," as Carey calls his part.

Although it is axiomatic that everyone is replaceable, tentpoles are the exception. "Tentpoles are irreplaceable," says producer Al Ragin. "If one leaves the show, the part is never recast."

Carey and Frances Reid, as his ever-loving wife, are the tentpoles around which the Horton family activities revolve. "When [the late] Ted Corday, who created 'Days,' first called me about doing my part, he told me it would be built around my character and my family," Carey recalls. He had no idea the show would see him enter his senior citizenship.

"Of course I've had occasional thoughts of leaving, but then I realize what a nice cushion this is. And I have done outside things." He is given time off to do TV movies that will be seen in prime time. In two of them, he has been cast as a doctor, but he thinks it is only coincidental. Yet after 15 years, it is only natural that large segments of the public think he's a real doctor.

Carey's favorite anecdote comes from a flight from Cleveland, where there had been a Heart Association convention. His seatmate lauded him: "That was a very good paper you read yesterday, doctor." sCarey accepted the compliment graciously. He hadn't been in Cleveland: The plane had set down there to take on passengers. He was en route home from New York.

After 15 years of the same role, he says, "What has kept it alive for me are the little comedy scenes they write for Frances [Alice] and me."

He has also started writing poetry. His first book, "Out of Heart," will be published by Quest-Everest House. He also is working on a TV series, "The Poet's Voice," on which he will narrate and explain modern poetry.

His TV wife, Frances Reid, is also a member of the original "Days" cast and a veteran of New York soaps: "As the World Turns," Edge of Night" and "Portia Faces Life."

Carey knows her character well: "She doesn't belong to my generation. She is of my mother's. I see her as my mother. I am unconsciously aware that she is older. You make your statement and play from the inside. I think she's 70. Like any job, it goes up and down, but I like it, and the people. I want to see it run forever. Mrs. Horton is very churchy. I relate to her on cooking, gardening and kids. I have great respect for homemakers."

Carey's tennis buddy, John Bernardino, a former baseball player turned actor, also had no plans to stay on "General Hospital" for 17 years.

"I never thought it would last this long. ABC had never had a soap on the air. I figured it would go for three or four months. Still, my character has good and bad moments. Lately, the good are few and far between. There's much more permissiveness now. Standards and practices [network censorship] have been loosened. I see it on all the shows. Yeh, I watch them. I believe the ABC shows are the best: 'All My Children,' 'Ryan's Hope' -- it's a good block of programming."

Bernardino too has his share of "doctor" stories, including a long-distance call from New York at 2 a.m., seeking advice for a sick child. (He referred the fan to a real pediatrician).

Rachel Ames (Audrey) is another long-termer on "General Hospital," sometimes, and sometimes not, married to Bernardino. She too loves her job. "John and I have known each other so well, it really is like being married. I spend more time here than at home. It's a way of life. We get involved with our scenes, and make the show as entertaining as possible. We don't get all the excitement the writers give the younger cast members, so we have to be inventive."

She has had her off-camera traumas: "When I was flirting with someone else while I was married to John, a man came up to me in a store and told me his wife almost had a heart attack, she was so upset about us. And when my character was on trial for murder, I couldn't get waited on in a department store.

"I too came on the show for 13 weeks. I had lymphoma, but went into remission. I'm a very longtime survivor," she laughs. Perhaps the longest in medical history, to be factual.

Another longtimer in Hugh Franklin (Dr. Charles Tyler on "All My Children," Carol Burnett's favorite show). Franklin is a member of the original cast starting Jan. 5, 1970. His career has included Broadway appearances with Helen Hayes, Constance Bennett, Ethel Barrymore, Eva Le Gallienne, the Lunts and Sir John Gielgud. His soaps include "Young Dr. Malone," "Love of Life," "As the World Turns," "Dark Shadows" and "Sceret Storm." He says, "When I started doing soaps, my actor-friends looked down their noses. Now I'm the one who's still working steadily."

Charita Bauer has been playing Bert on "Guiding Light" on CBS since 1950, when it was on radio. She made the transition to TV in 1952. She can't believe it's been 30 years.

"I love the show, but you know, I breathe easier when each three-month cycle is over. Five years ago, a producer said, 'Charita, I want to speak to you,' and I thought, God, this is it. I don't believe any actor ever has job security. You can't be smug. They can change the policy any time, and if it happens to me, I'll look for another job.

"Some of us who started very young have let daytime soaps be an integral part of our lives. It's good to know in September you still have a job. In recent years, Bert has gotten too mellow, I think -- too often she's like a mandarin doll. I try to keep a little of the old mettle. She's a woman devoted to her family, but she's also quite independent. Years ago, she bought a house, and told her husband afterwards. She had a lot of drive, and didn't take things lying down."

Bauer loves the recognition on the streets of Manhattan. "People look and smile and I smile back, or they practically faint dead away. Some give me a big hug and say, 'Wait until I tell my mother.' Recently though, it's also been 'Wait until I tell my daughter.' I believe young people watch because of the continuum, the familiarity. We go on like the river, we're part of their lives."

The most glamorous tentpole is Mary Stuart (Joanne on "Search for Tomorrow"). She has been that series' star since 1951. Interestingly, her personal life and Joanne's have paralleled over the years. Mary says, "Joanne and I are very much alike."

A glorious demonstration of fans' devotion to tentpoles was indicated when Bille Lou Watt (Ellie) finally married Larry Haines (Stu) on "Search for Tomorrow" in 1971. "The network received 17,000 pieces of mail and countless wedding gifts," Watt recalls.