Help finally to set the child's sleeping schedule.

Parents swear by this regular nap routine that promises to help finally nail down a baby’s sleep schedule.

You won’t find the 2-3-4 nap schedule in any parenting book. Rather, it’s one of those tools that has been passed from mom to mom, and from blog to blog. The idea is that you’ll have gradually increasing wake times between naps, with two hours before the first, three hours after that, and four hours just before bedtime. It’s designed for babies who can do with just two naps a day, a stage that usually occurs between six and 18 months old.

The structure helps families get on a schedule, making nap time less of a battle and helping parents predict when they’ll have windows in their day to run errands or see friends. And it might even help babies sleep longer at night.

Using a “laddered” nap approach like this makes sense from a scientific perspective, says Meg Casano, the co-founder of the sleep consulting group Baby Sleep Science. “Nap sleep is not driven in the same way as night sleep; it’s not controlled by the circadian rhythm,” she says. Rather, it’s about sleep pressure—the feeling of tiredness that increases the longer you’re awake. “You want your baby to have their highest sleep pressure at the end of the day before bed,” she says, because it will combine with their circadian rhythm and help them sleep better at night. If you’re trying this, she adds, be sure to start by setting a consistent wake time every day to help set your baby’s circadian rhythm. “If you have wild fluctuations in wake-up time, it gets to be a bit like jetlag,” she explains.

For readers who are just a little sleep deprived and need some help with the math, here’s what a 2-3-4 nap schedule might look like: Baby wakes up at 7 a.m. and goes down for her first nap at 9 a.m. If she sleeps until 10:30 a.m., the second nap would be three hours after that, at 1:30 p.m. Then, if she sleeps until 3 p.m., bedtime would be at 7 p.m.

Sounds easy, right? For Ashley Scott-Laidman, a mother of two in Hamilton, it was. She started using the 2-3-4 nap schedule when her first son dropped from three naps a day down to two at about eight months old. “It just made sense to me, and it fit with the routine I was trying to achieve,” she says. “I scooched up that first nap to get him on the schedule over a couple of days, and it made his naps longer, too.”

But no sleep schedule is one size fits all. Some babies who are ready for just two naps a day might not be tired enough to nap after being awake for only two hours, says Wendy Hall, a specialist in paediatric sleep and professor of nursing at the University of British Columbia. And some six-month-olds will still need a cat nap at the end of the day to see them through to bedtime. Signs that it might not be working include that your baby is fighting naps—a hint she can probably stay awake longer—or is overtired at night. “It really depends on the baby,” she says.

The 2-3-4 schedule also only works if your baby is sleeping a lot—for example, about three hours during the day and 12 hours at night—and with fairly consistent nap times. That’s 15 hours of sleep total, which is definitely on the high end of the sleep spectrum. According to The American Academy of Sleep Medicine’s guidelines, which Hall helped create, babies under one need 12 to 16 total hours of sleep a day, and toddlers ages one to two only need 11 to 14 hours.

The compromise could be to modify the schedule. That’s what Hayleigh Austin, a mother in Calgary, did. “I tried doing 2-3-4, but it just didn’t work,” she says, explaining that her baby only slept about 13 hours a day. Instead, she transitioned to two naps and a cat nap in the afternoon, and then to a 3-3-4.5 schedule. “That put him at that perfect place where if I put him down for a nap, he would fall right asleep,” she explains.

That’s a great solution, says Casano. “2-3-4 isn’t the schedule. It might be more like 2.5, 3.5, 4.5,” she says. “It’s almost like a math puzzle. But using a sleep ladder is helpful.”