Some babies sleep beautifully at night and then fight every single nap. Others will drift off anywhere, as long as they are in your arms or moving in the pram. And some wake after half an hour, crying, somehow more tired than when they went down.

Naps tend to get treated as night sleep in miniature. They are not. Daytime sleep runs to a rhythm of its own, and what settles your baby at bedtime will not always work in the middle of the morning.

The body clock does not clock off in the morning. It works right through the day, getting your baby ready for sleep at some moments and leaving them wide awake at others.

The longer your baby stays awake, the more sleep pressure builds. But that pressure only turns into sleep when the body is ready for it. In the early months those moments are scattered across the day. As the body clock develops, the day takes on a shape you can recognise, and naps start coming round at the same time each day.

It is also why the same nap can go two completely different ways depending on when it is offered. Too early, and your baby lies in the cot with no sleep to give. Too late, and tiredness has already tipped over, and an overtired baby fights sleep rather than falling into it.

Your baby will tell you, quietly. They go still, they lose interest in whatever had them busy, their gaze drifts. Small signals, the body letting you know the moment is here, before tiredness takes hold.

In the first year, while there are still two naps a day, the morning one tends to hold more active sleep, the kind where the brain is busy filing away what it has learned. The afternoon one tends to hold more deep sleep, the kind that restores the body.

So a long afternoon nap does not make up for a morning without one, and it does not work the other way round either. While the day still holds both, both are worth protecting.

Sleep comes in cycles, and at the end of each one there is a brief waking. Plenty of naps end right there, at the end of the very first.

During the day your baby never builds up as much sleep pressure, and most of what there is gets spent in that first cycle. Sleeping on from there comes down to self-soothing: being able to fall back asleep independently.

A baby who wakes at the end of the first cycle rarely wakes rested, and the rest of the day tends to show it.

When the nights are hard, the answer is often somewhere in the day.

A day with too little sleep leaves your baby overtired, and the body answers with stress hormones that keep them going instead of letting them slow down. Bedtime arrives with your baby wired instead of sleepy, harder to settle, and waking more often through the night.

Most children go on needing daytime sleep until around three or four, and some a little longer. What changes is how many naps there are and how long they run: three, then two, then one, and as each one drops away the ones that remain grow longer. The last one to go is the afternoon nap.

One day that nap is no longer needed. The pause still is. What stays is a quieter stretch in the middle of the day, no screens and nothing much happening, where the body slows down and the afternoon starts again in its own time.

Naps that never get past half an hour. Days when your baby will only drift off on the move. Late afternoons with no end in sight. Nights that got worse for no clear reason. On its own, none of that means much. Several at once, week after week, is worth a conversation. And if the breathing is always noisy in sleep, that conversation should be with your paediatrician.