One nap, most days
Some days one nap is enough and some days it isn't, and you find out which after you've committed.
The move from two naps to one is the biggest schedule change after the four-month shift, and it's slow. It usually happens somewhere between 12 and 24 months, and one-nap days appear well before the change is finished: most children do not fully settle on a single afternoon nap until between 15 and 24 months. Alternating days are the shape of the transition rather than a sign it's going wrong: one nap yesterday and two today is it working.
The morning wake window stretches a long way on one-nap days, from around three hours to four and a half or five and a half. The afternoon stretches by about as much. Total daily sleep drifts from about 13 or 14 hours down to 12 or 13. Those long mornings are hard on both of you.
If they show sleepy cues well before the new window, stretching in 15-minute steps with calm activities helps the body catch up.
What the nights do
Night sleep usually holds through this, but it moves.
On a two-nap day the familiar pattern holds: 10.5 to 11.5 hours, and a consistent point in the evening for bedtime. Wakings run from none to two, often to do with hunger or a developmental leap.
On a one-nap day, night sleep may stretch to 11.5 or 12.5 hours, and wakings can drop as sleep consolidates.
When your child has a one-nap day, I'd let bedtime come earlier, sometimes considerably. An earlier night is the safety net that keeps them from going past the point where settling gets harder. I think of it as the gift you give a toddler after a short day: it heads off the overtiredness that makes night wakings and early mornings more likely.
New skills, practiced in the crib
Walking arrives, and a stretch of broken nights arrives with it. The brain consolidates motor learning during sleep, particularly in naps, and toddlers practice new skills compulsively, including at night. Research on walking specifically found more night wakings and harder settling while the skill is being mastered.
So your 13-month-old wakes at two in the morning, standing in the crib, crying, with no idea how to get back down.
Standing up is easier than getting down, and working that out is part of learning it. I'd give them a minute before going in, and keep it calm and boring when I do. This phase resolves as the skill stops being new.
Bedtime is where it lands
Somewhere between 12 and 15 months your child discovers something powerful: they have a will. They can say no. They can refuse, protest and negotiate. Bedtime, being the moment of separation, becomes the natural arena for it.
Two things arrive at once. There's a sense of self, a desire to choose, an understanding that crying brings you back, and the discovery that "no" is a word with power. And there's a second wave of separation anxiety, usually around 12 to 15 months and more intense than the first. They now fully understand that you exist when you leave, and they have stronger preferences about who comforts them. They can imagine you leaving without yet being able to imagine you coming back. Responding to that doesn't make it worse. It's what builds the confidence to separate.
It shows up as harder bedtimes and crying when you go, more night wakings, only the right parent being acceptable, and intense clinginess before sleep.
And then your 14-month-old screams no at bedtime and runs off laughing.
That "no" is development rather than defiance. A calm, consistent boundary teaches them that limits are safe, and I'd expect them to keep testing it for a while yet.
Grief, frustration, and hope
Let's name what you might be feeling in The Shifting Dunes, because this stage carries a unique emotional weight.
- Grief: The nap that was once your guaranteed midday break is disappearing. Even when you're ready for the transition, mourning the loss is real.
- Frustration: Every day is a judgment call (one nap or two?) and getting it wrong means an overtired toddler at bedtime.
- Anxiety: You may worry that you'll never figure out the "right" schedule (you will). Or that this chaos will last forever (it won't).
- Guilt: When your toddler cries at bedtime, you may wonder if you're being too strict or not strict enough.
- Pride: Watching your child walk, talk, assert themselves, even when it's exhausting, is also deeply moving.
- Exhaustion: The transition can take 4-8 weeks. That's a long time to live with uncertainty.
The messy middle earns its name. I'd read what you're feeling as a sign you are in the hardest part of a necessary change, rather than as a sign you are doing it badly.
Staying on the same side
This transition tests partnerships. Every day brings a new nap calculation, a bedtime negotiation and a lot of feeling, and it's easy to turn on each other rather than on the problem.
The usual flashpoints: disagreeing about whether it's a one-nap or a two-nap day, and different thresholds for bedtime crying. An uneven share of the mental tracking. Resentment when one of you seems to get it right more often, and exhaustion shortening both your fuses. Different approaches don't mean you're failing as a team.
What helps is deciding about the nap transition together in a calm moment rather than in the middle of a bedtime battle. Have a phrase for when one of you needs backup. Say out loud that you're both doing your best in an uncertain phase. And remember you're on the same side even when you disagree about the nap count.
It does end. You're through when one-nap days run six or seven days a week and your toddler handles the long morning without melting down. Bedtime is stable within about half an hour most nights, and the second nap hasn't appeared in weeks.
What gets you through this is showing up and adapting, not finding the perfect schedule. I have never seen the perfect schedule exist.
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Stretching the wake window a little at a time helps the body adjust. I'd watch for genuine overtiredness alongside it, and I'd pause the whole thing on the days it clearly isn't working.