Daylight-saving time could cost some New York Marathon runners a whole lot more than an hour when most of the world sets its clocks back.

That means the racers can stay in bed just a bit longer — a delicious side effect that could lead to oversleeping and a missed start. It’s almost like the “Seinfeld” episode in which Jerry’s Olympic runner houseguest sleeps through the marathon’s start because of a Kramer-induced power failure.

The time shift could pose a real risk for chronic oversleepers. And some, like Christine Salomone, 27, are already taking steps to prevent the hourlong snooze button hitting that comes with daylight saving — which can turn a hazy wish for “five more minutes” of sleep into missed opportunities.

“I’m very paranoid about sleeping in,” says Salomone, a marketing manager for Sports Illustrated. Salomone plans to run in her second marathon tomorrow, but has a history of sleeping late at the worst possible times.

“I’m that girl you see running through airports trying to catch my flight — I always make it as the door is shutting,” she says.

“I may need a foghorn and a cup of coffee to get me out of bed, but I get there. The time change adds another variable into the mix, but with tons of different alarms, I should be OK.”

Salomone plans to wake up about 4:30 a.m. for her 10:30 start time. Just to make sure, though, she has asked her mom in Minnesota to call and wake her up. Her brother in Dubai, in a time zone eight hours ahead of New York, has been enlisted to call her, too.

Twin sisters Emily and Ally Chambers, 26, are also banking on a backup plan tomorrow in addition to their alarm clocks.

“My boyfriend is a bartender, so because of daylight saving and Halloween, he’s going to be working until at least 5 a.m.,” says Emily. “So he’s going to call me.”

Their older sister recently had a baby, and Emily has asked her to call as well, since new moms rarely sleep.

But her twin sister, Ally, is relying on her to make sure they’re both up. “She’s a snoozer,” says Emily.

“Any time you start to fool around with your body’s clock when you’re undertaking such a daunting task, there’s always the possibility that any tinkering can throw you off a little bit,” says Richard Finn, spokesman for the New York Road Runners Club, which organizes the marathon.

“But if by some strange quirk you forget to set your clock back, you’re only going to get to the start an hour earlier. It’s almost a built-in cushion, a sort of security blanket.”