A wake window is the stretch of time your baby can stay awake and content between two sleeps. Push past it and tiredness flips into overtiredness, and falling asleep turns into a fight.
You've probably seen a chart like this before. So here's the part the charts usually skip: these numbers are ballpark figures, not rules. Every baby is different, and the same baby is allowed to be different every day. Treat the chart as a compass, not a timetable.
| Age | Wake window | Naps per day |
|---|---|---|
| Newborn (0-6 wks) | 35-60 min | 6-8 |
| 2-3 months | 60-90 min | 4-5 |
| 4-5 months | 75-120 min | 3-4 |
| 6-8 months | 2-3 hrs | 2-3 |
| 9-12 months | 2.5-3.5 hrs | 2 |
| 12-18 months | 3-4.5 hrs | 1-2 |
| 18-24 months | 5-6 hrs | 1 |
Wake windows are shortest right after waking up and longest before night sleep. The first window of the day is almost always the tightest one.
Here's the reframe that makes wake windows useful instead of stressful: your baby is the source, the clock is the backup. These early tired cues show up before the fussing starts:
The first quiet tired cue is the best moment to start winding down. If you wait for crying, the window has usually already closed.
Not when the baby cries, but when the baby goes quiet. Catch the window and you put down a content baby instead of a tiny tornado.
When your baby stays awake too long, their body releases stress hormones that keep them wired. That explains the paradox every parent knows: the more tired the baby, the harder it is for them to fall asleep.
In the evening this often shows up as the witching hour, with crying that nothing seems to fix. It is not a parenting mistake and not something you need to repair. It is biology, and it becomes predictable once you know your baby's rhythm.
Instead of doing the math in your head: Darli learns your baby's rhythm and shows on the day ring when the next wake window ends. As a gentle nudge, not an alarm, and never as a verdict on how your day went.
One tap when they wake, one tap when they fall asleep. That's all it takes. Darli sorts the rest: the prediction, the history, and what today did differently.
Sleep, feeds, diapers: one tap is enough. Darli sorts the rest.
The stretch of time your baby can stay awake and balanced between two sleeps before tipping into overtiredness. It grows with age, from around an hour for a newborn to several hours for a toddler.
In the first weeks babies sleep very irregularly, so wake windows only help as a rough guide. From around 8 to 12 weeks they become more predictable and genuinely useful.
By the early tired cues: a glassy stare, eye rubbing, jerky movements, a first yawn. These show up before the fussing and are more reliable than any number on a chart.
No. The numbers are averages, not requirements. Some babies need shorter windows, some longer, and the same baby can swing from day to day. Your child is the reference point, not the chart.
Please don't. Wake windows are a compass for the days when you're unsure, not a schedule you answer to. Your gut feeling stays the most important sensor, and your baby's cues outrank any clock. Darli just gives you a second data point when you want one.
This guide is not a substitute for medical advice. If you are worried about your child, talk to your pediatrician or midwife.
