The guide
The app answers in five seconds; this is the paragraph behind it, for whoever wants it at 2 a.m. What the water means, the science it stands on, and what your child's sleep can and cannot do at each age — so your expectations can change on the same schedule their biology does. Written by me, kept current, every claim traceable. The dated lab log lives in the notebook.
Philosophy
A tide, never a deadline every age
This app will never tell you your child has to sleep at 14:20. That is its founding rule, and everything else here is a footnote to it. The screen you look at is water — a tide of sleep pressure rising toward a shore — and the times it implies are wide, soft windows. Never appointments.
What this app will never do every age
NaniNani exists to lower a tired parent's stress, not to become one more thing you get graded on. That reads like a slogan right up to the moment a screen has to decide whether to show a countdown — so I wrote it down as rules a code review can fail against. This is the promise, in the form of nine things the app will never do to you.
Why NaniNani stays calm every age
I built NaniNani to take stress off you, not to hand you one more thing to be graded on.
Why the app talks the way it does every age
Every sentence in this app is written under one test: if a parent reads this at 3 a.m. after the fourth waking, does it lower their shoulders or raise them? This article is the reasoning behind that test — why the app says "longer than the usual 55m — that's fine" instead of just showing you a timer, and why it will sometimes tell you to go rest.
The science
What sleep pressure actually is every age
Everything this app shows you rests on one piece of biology: sleep pressure. It is not a metaphor I invented for the app's tide — it is the best-established mechanism in sleep science, called Process S in the literature since 1982, and it is the reason "wake windows" work at all. If you understand this one idea, the whole app becomes obvious.
Using NaniNani
How to read the water every age
The home screen is a tide. The waterline is your child's sleep pressure — the real, physical drive to sleep — rising while they are awake, draining while they sleep, drawn against their own personal threshold: the level at which they, historically, fall asleep easily. The percentage riding the "now" line says how close the water is to that shore. 100% means "sleep would come fast now". It never means "they must sleep now". Nothing on this screen is a deadline; here is how to read it.
Hands-on
How to settle a newborn 0-8w · 2-4m
Here is the honest frame first: you cannot make a baby sleep. Nobody can — "you can force wakefulness upon sleep, but you cannot force sleep upon wakefulness," as Weissbluth puts it. What you control is the opportunity: catching the moment when pressure is high, then raising the level of soothing until staying awake becomes the hard option. Everything below is drawn from the two books this app is built on, and it is what my partner and I actually leaned on.
The morning that started too early 4-7m · 7-12m · 12-24m · 2y+
The day counts from when they woke, not from the time on the wall. If your child was up at ten to six, the first nap is due earlier, and so is everything after it, bedtime included. The instinct to hold the usual schedule and "reset the day" is the one thing that reliably makes an early morning worse: it stretches the first window past what a child who has been awake since dawn can hold, and hands you a second wind by mid-morning.
When they wake at two in the morning 0-8w · 2-4m · 4-7m · 7-12m · 12-24m · 2y+
A waking is not a broken night. It is the visible part of something that was happening all night anyway: a child surfaces between sleep cycles every twenty to forty-five minutes, and most of those surfacings you never hear about. Tonight you heard about one. That is the whole of what has been established so far — everything else is what you decide to do next, and almost none of it needs deciding at two in the morning.
The day the nap never happened 4-7m · 7-12m · 12-24m · 2y+
Bedtime moves earlier tonight — thirty to sixty minutes — and that is the whole plan. A missed nap is one of the few sleep problems with a single, boring, effective answer, and the answer is available to you this evening. You do not have to fix the day; you only have to shorten it.
When the nap is short 4-7m · 7-12m · 12-24m · 2y+
A twenty-five-minute nap is not a failed nap. It is a partial one, and the difference matters, because it tells you exactly what to do next: the sleep that happened drained real pressure, so the next stretch of awake time will run shorter than usual. That is the whole practical consequence. Not a ruined day — a shorter day.
What to expect
Four to seven months 4-7m
This is the era when structure actually shows up — the one every schedule chart on the internet quietly assumes. Around four months, sleep architecture becomes essentially adult: sleep begins in deep non-REM, cycles maturely, and responds to timing. The day starts organizing around anchors, and for the first time, watching the clock becomes as useful as watching the child.
Seven to twelve months 7-12m
This is the most orderly stretch of the first two years — enjoy it. The day settles into a shape so common it's almost a uniform: wake around 6–7 a.m., nap near 9, nap near 1, bed between 6 and 8 p.m. By nine months, 91% of babies take exactly two naps. If the first half-year was weather, this is climate.
The first eight weeks 0-8w
If your baby is under two months old, here is the single most useful thing I can tell you: the scattered, clockless sleep you are looking at is biology running exactly on schedule. Nothing is late, because the machinery that could be late has not switched on yet. This article is the reassurance most sleep apps know and don't say — they simply go quiet under two months and let you fill the silence at 3 a.m. with "my baby isn't doing the thing the app is waiting for."
The second year 12-24m
One thing dominates the second year: the move from two naps to one. It is the biggest, sloppiest transition in all of childhood sleep, and knowing its true shape spares you months of second-guessing. The headline numbers: at twelve months, 17% of children are on one nap; at fifteen months, around half; at eighteen months, 77%; by twenty-one months, 88%. The median lands near a year and a half. So if your friend's fourteen-month-old dropped to one nap and yours hasn't — both children are dead on schedule.
Two to four months 2-4m
Somewhere in these weeks, the clock switches on. The melatonin rhythm that simply didn't exist at birth becomes observable around nine to twelve weeks and steadies at thirteen to fifteen; body temperature and cortisol fall into daily rhythm; day and night become real categories for your baby, not just for you. This is the single fastest period of change in the whole first year — "the most rapid consolidation in infant sleep regulation occurs in the first four months" — and it changes what you can fairly expect, in stages, not all at once.
Two years and beyond 2y+
The nap is not over. That's the first thing to know, because around the second birthday almost every child stages a convincing performance of being done with it — and almost none of them are. At age three, 92% of children still nap; even at four, more than half do. The performance is boundary-testing, a toddler discovering that naptime is negotiable in a way gravity is not. The books' answer is the same calm one: keep offering the midday rest, unmoved, for about an hour. In most cases, after a couple of days of theater, the napping resumes as if nothing happened.
What moves and what holds every age
Over the first two years, almost every sleep number you can watch will travel a long way: bedtime will fall by about three hours and then climb most of the way back, naps will go from four or five a day to one, and day sleep will shrink from six hours to two. One number holds still through all of it — the night. Knowing in advance which numbers are travelers and which one is the anchor spares you a great deal of worry, because the travelers look like problems and aren't.