Have you ever heard that babies sleep better and longer when their day is approximately 12 hours long? It’s true! This is my general rule of thumb when working with little ones, and it’s especially applicable for babies in the 9 month to 2 year old range.
A 12-hour day simply means that when you add together your child’s “awake” hours plus their “napping” hours, the total should equal approximately 12 hours before bedtime.
Now, there is some flexibility here, you can go 30 minutes in either direction, because before age 2 you should never have a set bedtime for your kiddo (read more on that here). Your child’s bedtime is determined by their morning wake time and their nap(s) duration. But, if your wake windows are on point, and your child is sleeping adequately for naps, your day should naturally add up to approximately 12’ish hours.
Here's how that could look for your little one!
Ideal Schedule for a Two-Nap Day (7’ish months to 15’ish months) Awake 2.5 hours Nap 90 min Awake 3 hours Nap 90 min Awake 3.5 hours Bedtime *Note how adding the awake time and nap time equals 12 hours
This does not have to be perfect, there is some wiggle room here, but in general this would be an ideal schedule. Ideal Schedule for a One-Nap Day (12 to 15'ish months)
There is less wiggle room when a child drops to just one nap per day as you only have one shot to get that nap sleep in!
Awake 5 hours
Nap 2 hours
Awake 5 hours
Bedtime
*Note how adding the awake time and nap time equals 12 hours
Now, if your child habitually naps more, or less, you can adjust the awake times a bit on either end. However, I strongly recommend to parents with babies taking just one nap a day to keep them awake for five hours in the morning before offering a nap, so that in the event baby takes a short nap, they aren’t stretched too long on the second half of the day, thereby getting overtired, or go to bed too early i.e. 5:30 pm or 6 pm which often results in a 5 am to 6 am waking! This, unfortunately, is a pattern that many kiddos can get stuck in and is very challenging to get a little one out of! Therefore, if your babe has an early morning waking on a certain day, do your best to get an extra-long nap in, even if you have to assist that nap, so their bedtime doesn’t fall too early.
I have seen that there is more variability in this 12-hour rule with babes who are 7 months or less taking three naps per day. Because of that third nap, their nap sleep can vary quite a bit day-to-day, and their days can often extend a little more easily to 13 or so hours without too much disruption to overnight sleep.
While most babies in general do best on a 12’ish hour day, there are some extra sensitive sleepers out there, who sleep much, much, better overnight when their total day does not exceed 12 hours.