Baby Sleep Guide

1. What is a wake window?

A wake window (WW) is the ideal length of time a baby can be awake between sleeps before over-tiredness causes cortisol to spike and sleep to deteriorate. Too short and naps will truncate; too long and bedtime becomes a battle.

• 0–1 mo: 45–60 min
• 1–3 mo: 60–90 min
• 4–6 mo: 1.5–2.5 h
• 6–9 mo: 2–3 h
• 9–12 mo: 3–4 h
• 12–18 mo: 4–5 h
• 18–24 mo: 5–6 h

2. Sleep regressions

Regressions coincide with developmental leaps (brain maturation, motor milestones, separation anxiety). A previously great sleeper wakes frequently — usually for 2–6 weeks. Do not change the schedule; keep the same routines.

• 4 months: adult-style cycles emerge. Practice drowsy-but-awake transfers.
• 8–10 months: separation anxiety + crawling + teething. Practice new skills during the day.
• 12 months: keep 2 naps; don’t drop to 1 too early.
• 18 months: toddler defiance. Offer small choices but keep bedtime fixed.

3. Sleep training methods compared

4. Nap transitions (3→2→1)

• 3 → 2 naps (6–8 mo): trigger when third nap shrinks to under 10 min or bedtime drifts late.
• 2 → 1 nap (15–18 mo): toddler refuses the morning nap or wakes frequently at night. Single nap of 1.5–2 h around noon works best.

5. Bedtime routine template

1. Bath + massage (10 min)
2. PJs + diaper (3 min)
3. Feed in a dim room (15 min)
4. Lullaby + book (5 min)
5. Into the crib drowsy-but-awake

Total 30–40 min. Consistency > perfection.

6. When to consult a pediatrician

• Loud snoring or pauses in breathing — possible sleep apnea
• Sharp drop on growth curve
• 5+ night wakings lasting longer than 6 months
• Sudden onset of head-banging, teeth-grinding, or night terrors

This guide summarizes AAP guidance; it is informational and not a substitute for medical advice. Contact your pediatrician for anything that worries you.

7. How to use this tracker

Baby sleep is not measured in hours but in segments. The tracker is built to capture that flow with two taps per segment instead of a paper diary. Enter your baby’s birth date at the top and the tracker picks the wake-window band for the current age. Each "wake at" and "asleep at" tap closes a segment and updates a horizontal bar showing accumulated awake time. At 80% of the recommended window the bar shifts to a soft warning shade; past 100% it turns deep red — a strong visual cue that the next nap or bedtime is already due. Every measurement lives in localStorage only; nothing is sent to a server.

At night, a separate "wake-up" tally accumulates each rouse. If five or more wake-ups persist for six consecutive months, the tracker surfaces a gentle "see a pediatrician" badge. The badge is a signal, not a diagnosis — the decision to seek professional input always belongs to the parent and clinician.

8. Five quirks of the Korean baby-sleep context

Anglosphere sleep guidance summarises global recommendations well, but a few features of typical Korean households deserve their own callout. The tracker was designed with these in mind.

• Room-sharing as the default. Most Korean families keep babies in the parents’ room well past 12 months, sometimes through age 2-3. The AAP recommends room-sharing (separate sleep surfaces) for the first year; the tracker’s wake counts apply identically to room-shared sleep.
• Apartment noise. Dense apartment living makes inter-floor noise a recurring concern for Ferber-style training. The tracker is method-neutral — pick whichever fits your family and neighbours.
• Extended breastfeeding and night feeds. Many Korean mothers nurse through 6-12 months with 1-2 night feeds. The AAP recommends a gradual reduction after six months. Logging feed times alongside wake-ups reveals correlation visually.
• Grandparent care on weekdays. When grandparents handle weekday care, nap routines can drift. The tracker does not support per-caregiver accounts, but a shared PWA shortcut on a household tablet keeps everyone on the same dataset.
• Tie-in with KCDC well-baby checks. Capture the rolling 7-day average at the 14-35-day, 4-6-month, 9-12-month and 18-24-month checks and bring it to the pediatrician — the 10-minute visit becomes much more concrete.

9. Three safety rules to never bend

Sleep-training style varies by family, but three AAP safe-sleep rules should hold regardless of method.

1. Back to sleep. Place infants on their backs for every nap and night through 12 months to reduce SIDS risk. Side or stomach positions are unsafe.
2. Bare crib. No pillows, blankets, stuffed animals or bumper pads — only a firm mattress with a snug fitted sheet. Heavy quilts (common in Korea) are unsafe under one year.
3. Room-share, never bed-share. Sharing a room reduces SIDS; sharing a bed increases suffocation risk from parental rolling. The tracker logs both equally — safety remains a separate decision.

10. Common patterns the tracker exposes

• Last nap ends too late. A bedtime gap shorter than the recommended wake window stretches bedtime out. The tracker flags it and suggests waking the last nap 30 minutes earlier.
• Cat naps (30-40 min). One-cycle naps mean the baby never bridges into the second cycle. Shorten the next wake window by 5-10 minutes or tighten the sleep environment (darkness, white noise) to encourage a transition.
• Weekday/weekend divergence. Weekends with grandparents or outings often produce visibly different bars in the 7-day chart. Consistency is the highest-leverage variable.

11. Explicit limits

This tracker does not address sleep apnea, EEG findings, pediatric depression, or anything else that needs medical diagnosis — those belong to pediatricians or pediatric mental-health specialists. The tool is also method-agnostic: Ferber, CIO, No-cry and Chair are presented side by side without endorsing any of them. The best sleep routine is not a single right answer; it varies by family. The tracker’s job is to give that decision the data it deserves.