(CNN) -- Crossing time zones can drain travelers, just like looking after young children can exhaust parents. Put them together, and the result can be overwhelming.
Managing junior jet lag can make the difference between a fun family holiday and a traveling temper tantrum.
But getting kids to sleep on a schedule can be a challenge at the best of times. Throw in a multihour time difference and vacationing families might have the makings of a meltdown on their hands.
Sleep specialist Russell Rosenberg, chairman of the National Sleep Foundation, suggests trying to adapt kids' schedules in the days leading up to a trip, instead of waiting until the first night of the vacation.
"The best advice is probably to adjust the bedtime to the destination bedtime, even before you go," he says.
Even with ample preparation, though, many traveling parents don't know what to expect when their children encounter a new time zone.
Some are pleasantly surprised. Debbie Dubrow, blogger at DeliciousBaby.com, has taken her three children from their home in Seattle to countries including Spain, France, Italy, Britain and Turkey.
When she and her husband took their 6-month-old son to Paris, the baby took a three-hour nap in a stroller -- enabling his parents to enjoy a multicourse meal at a Michelin-starred restaurant. "He wouldn't have taken that long a nap at home," Dubrow says.
But an epic nap isn't always the best solution. It can prevent children from going to bed on schedule, and cause them to wake up at unsociable hours -- and vex their parents.
"If the child must nap, try to limit it to 15 to 30 minutes," advises Dr. Joseph B. Rosen, director of Sleep Medicine at Pediatric Pulmonary and Sleep Specialists in Dallas. "Generally speaking, napping earlier in the day is better, as opposed to in the afternoon or evening, local time."
Experts agree that children who have slept well in the weeks leading up to a trip are the most adept at adapting to a new time zone. "Well-rested children tend to handle jet lag much better than adults do," says Dana Obleman, an infant and child sleep expert.
She suggests putting young children to bed at the same time every night at least four weeks before the trip, and letting them sleep for about 10 to 12 hours. Then they're ready to roll with their new schedules as soon as the trip begins. "When you get to your new location, try to get into the new time zone as quickly as possible," she says. "That tends to help the body clock adjust."
But no matter how much sleep youngsters have accumulated in the days leading up to a journey, a long flight across several time zones can scupper any sense of a schedule.
Erik Budde, owner of the website TravelWithYourKids.com, recently flew from San Francisco to Sydney, Australia, with his 7-year-old daughter and 2-year-old son.
Budde's family has developed strategies for helping their children to sleep on long-haul flights, and not all of them rely on nature taking its course. "We usually go with a drug-aided approach," he says. His family finds that Benadryl helps the kids sleep while they fly, which makes them better rested for the start of their trip.
But McNeil Consumer Healthcare, the company that makes Children's Benadryl, isn't so sure. "As noted on the label, the product should not be used to make a child sleepy," spokeswoman Jodie Wertheim writes in an e-mailed statement. The National Sleep Foundation's Rosenberg also advises against using over-the-counter medication to help children adjust to a new time zone.
But getting through the flight is only one phase of Budde's strategy. He has his youngsters hit the ground running, literally.
He recommends taking the kids to a playground right away for two reasons: "One, to get them to burn off some energy," he says. "Two, to get them exposed to light."
Sunlight is the most potent tool in helping travelers adjust to their temporary time zone, doctors say. A bright electric alternative also can help, they say. "Light is the most powerful time cue that we use," says sleep physician Neil Kline, a representative of the American Sleep Association. Soaking up sunshine or other bright light in the morning, with limited exposure in the late afternoon, helps to reset a traveler's clock.
So does doing as the locals do, and getting on the destination's schedule as soon as possible. "This means sleeping, eating meals, exercising and doing social activities in accordance with local time," Rosen advises.
Also keep the kids hydrated. "Make sure that they drink plenty of water," he says. "Dehydration is responsible for some of the jet lag symptoms we feel."
But the adjustment will not happen right away. Sleep experts say that for each time zone a traveler crosses, expect to need about 24 hours to acclimate to the new schedule. "For most of us, adults and children, it takes a few days to adjust," says Rosenberg. "A day per hour change is a rule of thumb."
Even with the best-laid plans, a long trip with young children will most likely mean early mornings for parents, even if the nights are late. Budde says he has not yet figured out a way to get his kids to stay in bed after they wake up on a trip, even at 4 a.m.
"It's easier to get them to go to sleep than to get them to stay in bed against their will," he says.
For parents, waking up early with kids in far-away countries sounds a lot like mornings at home.