Nap transitions: from 3 to 2 to 1 nap

How napping changes

With age, children sleep less during the day, while night-time sleep stays about the same length. In app data from over 175,000 babies, sleep in 24 hours fell from an average of 14.8 to 12.5 hours between 3 and 18 months – almost only because daytime sleep became shorter, from 226 to 101 minutes. The number of naps fell from almost four to one (Paavonen 2026). The Zurich longitudinal study describes the same: in the first year daytime sleep decreased, and night-time sleep even became somewhat longer until the first birthday (Iglowstein 2003).

Important: the big numbers from app data are averages. The researchers stress how different children are and that such differences show up early and last long (Paavonen 2026).

From three to two naps

No study gives a fixed age for this change. In app data from 841 children, between three and seven months two naps of about an hour and a half and a night of about ten and a half hours usually emerged (Mindell 2016). In an American long-term study, two naps were firmly established at 9 to 12 months (Weissbluth 1995).

Moon Hour accounts for three naps from four to six months and for two from six months. These are starting values; if your child does something different, the app learns this from your entries.

From two to one nap

In Weissbluth’s long-term study, two naps usually became a single afternoon sleep between 15 and 24 months (Weissbluth 1995). In the app data of Paavonen and de Bie, children at 18 months took on average one nap (Paavonen 2026). It is rare for children to stop altogether at this age: in the Zurich study, 96% still slept during the day at a year and a half (Iglowstein 2003).

Moon Hour accounts for one nap from 15 months. If your child still takes two, you set the number in the app; the wake windows then adjust.

Why transitions can be bumpy

When a nap drops away, the remaining ones get longer. In the app data, the remaining naps made up about 88 to 89% of the lost sleep at the early transitions, but only about 79% at the change from two to one (Paavonen 2026). During this time children often sleep a little less during the day than before.

Daytime and night-time sleep are connected: in a study from Québec, children with more daytime sleep at the same age had somewhat less night-time sleep, both at 5 and at 17 months (Fréchette-Boilard 2026). In another study, children who still habitually napped at midday went to bed later in the evening and took longer to fall asleep than children without a midday nap (Akacem 2015).

How long the one midday nap is

When only one nap is left, it gets longer. In Weissbluth’s long-term study, the midday nap between two and six years most often lasted two hours (Weissbluth 1995). From 15 months, Moon Hour starts by accounting for about two hours and then learns how long your child really sleeps. If the midday nap ends too late, the app suggests ending it so that enough wake time is left before the night; this gap is an experience value.

Napping in child care

Child care plays a part too: in an Australian study of children aged 1 to 4½ years, younger children napped somewhat less often on child care days than on days at home; the researchers suspect fixed nap times in child care as the reason (Normore 2026). In Moon Hour you can enter child care days; naps in child care don’t count toward learning.

And the last nap?

Children give up the last nap much later: fewer than 2.5% stop altogether before their second birthday, and by five years 94% have stopped (Staton 2020). More on this in the article on the midday nap.

If you are worried

Experts recommend contacting your paediatrician or your local out-of-hours medical service if you are worried.