Your baby did not forget how to sleep. Their sleep cycles changed shape.
Around 4 months, sleep cycles get longer and lighter and a baby surfaces between them — which is why a baby who slept in 3-hour blocks starts waking every hour or two. This page has what the published guidance actually says, a tool that measures the gap between your baby’s wakings against the infant sleep-cycle length, the safe-sleep rules that never change, and a printable night log. No account. No upload.
Safety note: This page is educational record-keeping support. It restates published guidance, logs times you enter, and reports the interval pattern in those times. It does not diagnose, triage, or treat, it does not decide whether your baby is having a sleep regression, and it cannot tell you why your baby is waking. Nothing here replaces safe-sleep guidance or your pediatrician. Keep placing your baby on their back for every sleep until they are 1 year old, and contact your pediatrician — rather than relying on this page — if your baby is not gaining weight or is losing weight, is feeding less than usual, has fewer wet or dirty diapers than usual, has abnormal breathing during sleep, is hard to wake, is unusually lethargic or floppy, is feverish, is vomiting, or if anything simply feels wrong. Call emergency services if your baby is unresponsive, struggling to breathe, turning blue, or has a seizure. For your own mental health, Postpartum Support International and the 988 Lifeline are there for parents too. DadYolked is a record, not a diagnosis.
What the guidance says
The published facts, so nobody has to guess at 3 a.m.
Every figure below is restated from the cited source. Nothing on this page is a stronger claim than the source makes.
Question
What the source says
Source
Infant sleep-cycle length
Mean 50–60 minutes (range 30–70); roughly 60 minutes through the first year
“Babies do not have regular sleep cycles until about 4 months of age.”
AAP HealthyChildren: Getting Your Baby to Sleep
Newborn sleep
About 16 to 17 hours a day, often in 1- to 2-hour stretches
AAP HealthyChildren
Total sleep, 4–12 months
12 to 16 hours a day, including 3–4 naps and around 10–12 hours at night, possibly broken into stretches
Sleep Foundation
Wakings at 4 months
Waking 1 to 3 times a night for feeding or comfort is normal
Sleep Foundation
Typical bedtime at 4 months
Between 6:30 p.m. and 8:00 p.m.; an earlier bedtime can help prevent overtiredness
Sleep Foundation
How long it lasts
In most cases a few days to a few weeks — it depends in part on sleep habits
Sleep Foundation
Safe sleep position
On the back for every sleep until 1 year old — not on the side or stomach, not even for a nap
NICHD Safe to Sleep® / AAP Task Force on SIDS
Swaddling
Stop swaddling once a baby starts rolling over on their own, usually around 3 months
NICHD Safe to Sleep® / AAP
The honest caveat, up front: Sleep Foundation states that not all babies have a 4-month sleep regression, that individual variation in infant sleep is considerable, and that many babies do not sleep through the night even at 12 months. So do not treat the label as a diagnosis, and do not treat a bad week as evidence that you are doing something wrong. Treat the pattern in your own baby as information.
Pattern analyzer
Log the wakings. See the interval pattern.
This is the part nobody does at 2 a.m.: the gap between wakings. Log when your baby went down, when they woke, and when they were up for the day. The tool reports each interval, the longest stretch, and whether those gaps cluster around whole sleep cycles — because wakings that land near a cycle boundary and wakings scattered at random mean different things to a pediatrician. It does not decide why your baby is waking.
DateDown atWake 1Wake 2Wake 3Wake 4Wake 5Wake 6Up for day
Nothing logged yet
Fill in at least one night with a bedtime and one wake time. The analyzer reports the gaps between wakings in minutes and compares them with the published infant sleep-cycle band of 50–60 minutes (range 30–70).
Your generated handoff note will appear here.
Privacy: this analyzer runs entirely in your browser. Nothing is saved, submitted, or uploaded, and there is no account. Closing or refreshing the tab clears every entry.
What actually helps
The published steps, in rough order of effort.
These are the caregiver actions the cited sources actually recommend — not sleep-training doctrine, and not a promise that any of it works tonight.
The one to try first
Put them down drowsy, not asleep.
AAP HealthyChildren: put babies to bed when they are drowsy rather than waiting until they are asleep, so they learn to fall asleep on their own in their own bed. The stated reason is that a baby who fell asleep in your arms may struggle to go back to sleep when they surface at a cycle boundary.
Night wakings
Wait a minute before going in.
AAP: do not rush in to soothe a crying baby, because babies need time to put themselves back to sleep. Sleep Foundation suggests waiting about a minute to see whether they can self-settle, and notes it is normal for even a 6-month-old to wake and go back to sleep after a few minutes. If they need you, go — feeding, a dirty diaper, or illness are legitimate reasons.
Night feeds
Fed fast, dark, quiet, back down.
Sleep Foundation: if you need to feed during the night, do it as quickly as possible with the room dark and quiet, then avoid playing with or stimulating your baby and put them back to bed. It also notes babies may be more distracted at daytime feeds around this age, which can leave them genuinely hungry at night.
Day and night
Contrast the two.
Sleep Foundation: during the day keep your baby active with playtime and natural light; at night keep the room dark, quiet, and calm. That contrast is what helps adjust a developing internal clock, and it is the least controversial thing on this list.
Separation anxiety
Reassure without restarting.
Sleep Foundation suggests that if your baby cries from separation anxiety when you put them down, resist pulling them back out of the crib; instead comfort them where they are, with a soft voice and a light rub of the head, then quietly step away and let them settle.
Your own shift
Protect one real block.
Sleep debt is the thing that makes a hard week dangerous rather than just hard. Split the night so one adult owns a genuine stretch, and take the early-morning change and dress so your partner can go back to sleep. Sleep Foundation lists caregiver self-care as part of the plan, not a luxury.
Non-negotiables
Nothing about a bad week changes these.
A sleep regression is exactly the moment people start improvising. The safe-sleep rules do not have a regression exception, and none of the tips above should be read as licence to change them.
Never change the sleep positionNICHD Safe to Sleep® and the AAP Task Force on SIDS: place all babies — including preterm babies and those with reflux — on their backs to sleep until they are 1 year old. Not on the side or stomach, not even for a nap. NICHD states that putting a back-sleeping baby on the stomach or side increases SIDS risk by up to 45 times.
Never add soft beddingKeep comforters, quilts, pillows, and blankets out of the sleep area, and avoid soft surfaces like couches, waterbeds, memory foam, and pillow-top mattresses. Use a firm surface and a CPSC-compliant crib, bassinet, or play yard.
Stop swaddling at rollingNICHD: once a baby starts rolling over on their own, swaddling increases the risk of suffocation and strangulation. Stop swaddling when rolling starts, usually around 3 months — and keep a swaddled baby on their back.
Do not use sitting devices for sleepCar seats, strollers, carriers, and slings are not safe regular sleep areas or nap spots. If your baby falls asleep in one, move them to their sleep space as soon as you are out of the vehicle. Inclined surfaces and slumped-over positions can block a baby’s airway.
Do not trust a monitor to prevent SIDSNICHD is explicit: no product can prevent SIDS, and these monitors are not effective at detecting or preventing it. If you use one for another reason, still follow every safe-sleep recommendation.
Do keep them in your roomFor at least the first 6 months, NICHD and the AAP advise room sharing — baby near your bed but in their own separate sleep space — which is safer than bed sharing and easier for night feeds and comfort. If you feed in your bed, clear away all soft bedding first and put baby back in their own space afterwards.
When to call
The published call-the-pediatrician triggers.
A regression is not on this list, and none of these are things to wait out. Sleep Foundation says to talk to your doctor about increased night wakings, and to contact your pediatrician if you also notice any of the following alongside them.
GrowthLack of growth or weight gain, or weight loss.
FeedingA reduced number of feedings, or your baby is feeding poorly or refusing feeds.
OutputChanges — especially a reduction — in urination or bowel movements.
BreathingAbnormal breathing during sleep. Sleep Foundation says parents should discuss this with their pediatrician.
Anything that feels wrongUnusual lethargy, floppiness, fever, unresponsiveness, or a gut feeling you cannot explain. Emergency services first if your baby is unresponsive, struggling to breathe, turning blue, or has a seizure.
And your own healthPostpartum depression happens to dads and is commonly missed because nobody screens fathers. If you are not sleeping, not eating, feeling detached or hopeless, or frightened by your own mood, tell your own doctor. Postpartum Support International and the 988 Lifeline are there for you as well as your partner. Free 24/7 support for parents: HRSA’s National Maternal Mental Health Hotline, 1-833-TLC-MAMA (1-833-852-6262) — free, confidential, English and Spanish. HRSA’s own words: “New parents: you’re not alone.”
App comparison
Do sleep apps measure the pattern, or just log it?
Most track how long the baby slept. The question this page starts from is different: how long were the gaps, and do they line up with sleep cycles?
Feature
Generic baby trackers
Sleep-only apps
Notes apps
DadYolked
Sleep duration logging
Yes
Yes
Manual
Yes
Wake-time capture
Sometimes
Yes
Manual
Yes
Interval between wakings computed
Rarely
Sometimes
No
Yes
Compared against cycle-length guidance
No
Rarely
No
Yes
Longest uninterrupted stretch
Sometimes
Yes
No
Yes
Feeds, diapers, and meds in the same record
Yes
No
Manual
Yes
Night-shift handoff for the other adult
Sometimes
No
Manual
Yes
Dad-focused, one-handed logging
No
Sometimes
No
Yes
Apple Watch / Siri / widgets
Sometimes
Sometimes
No
Yes
Pediatrician-ready summary
Sometimes
Sometimes
No
Yes
No account required
No
Sometimes
Yes
Yes
Local-first, no upload
No
Rarely
No
Yes
Read the table honestly: sleep-only apps are genuinely good at duration, trends, and gentle wake windows, and some do show night wakings. What almost none do is put the interval in front of you as a number to take to an appointment — and none of them keep that night in the same record as the feeds, diapers, medicine, and the adult who took the second shift.
Printable log
A paper night log and handoff sheet for the fridge door.
Night Waking Log & Caregiver Handoff
Use your child’s qualified care team for all medical decisions. This sheet helps you record when your baby woke and what you tried. It does not provide advice, diagnosis, or treatment recommendations, and it does not decide whether your baby is having a sleep regression. Keep following safe-sleep guidance: back to sleep for every sleep until 1 year old.
Baby / week starting
Who is on tonight (first half / second half)
Pediatrician and after-hours number
Any concern from the published trigger list (growth, feeding, diapers, breathing, lethargy, fever)
Night log
Date
Down at
Wakings (times)
Longest stretch
Last wake / up for day
What helped
Who handled it
What the caregiver needs to know
Feeding plan overnight (who feeds, how, and what happens if baby will not settle)
How baby is settled back to sleep (what works, what does not)
Safe-sleep setup confirmed (back to sleep, firm surface, nothing soft in the sleep space)
Question for the pediatrician — and any daytime symptoms to mention alongside the wakings
Care-team answer / teach-back, and who owns the follow-up
Privacy: this blank worksheet does not save, submit, or upload anything you write. Printed notes and app exports can still contain private family health information — store them securely and share only what the care team needs through channels it accepts.
FAQ
Sleep regression — quick answers for dads.
Is the 4-month sleep regression real?
It is a real developmental change, although the word “regression” is misleading and not every baby shows it. AAP HealthyChildren states that babies do not have regular sleep cycles until about 4 months of age, and that newborns sleep about 16 to 17 hours a day but may only sleep 1 or 2 hours at a time. Sleep Foundation describes the 4-month period as a transition from newborn sleep patterns into more mature sleep stages, says the timing varies, and states plainly that not all babies have a 4-month sleep regression — some have no detectable change at 4 months, and others have difficulty a few months earlier or later. Individual variation in infant sleep is well documented. What is genuinely useful is not the label but the pattern in your own baby’s wakings, which is what this page measures.
Why does my baby suddenly wake every hour or two?
The published explanation is about how sleep cycles work, not about your baby forgetting how to sleep. Infant sleep cycles are short: the AASM infant sleep-scoring reference puts healthy term infant sleep cycles at a mean of 50–60 minutes (range 30–70 minutes), and pediatric sleep reviews describe infants cycling roughly every 60 minutes through the first year, versus 90–120 minutes in adults. At the end of each cycle a baby surfaces into lighter sleep and may briefly wake. A baby who was put down already asleep can find their surroundings changed and need help to resettle, which is why Sleep Foundation lists helping your baby learn to fall asleep in bed as one of the main things caregivers can do. This page's analyzer measures the interval between your baby’s wakings so you can see whether they are landing near whole sleep cycles or are all over the place. It cannot tell you why your baby is waking.
Does the night waking analyzer diagnose a sleep regression?
No, and it is deliberately built not to. It does arithmetic on the times you type: the gap between consecutive wakings in minutes, the longest uninterrupted stretch, and how many of those gaps fall inside the published infant sleep-cycle band. It then compares your waking count with the published expectation that waking one to three times a night for feeding or comfort is normal at this age. It does not decide whether your baby is having a regression, does not assess development, and cannot tell you why your baby is waking. If your baby is not gaining weight, is feeding less, has fewer wet or dirty diapers, or has abnormal breathing during sleep, contact your pediatrician rather than relying on this tool.
Do the analyzer and the night log save or upload anything?
No. Both run entirely in your browser tab. Nothing is saved, submitted, or uploaded, there is no account, and closing or refreshing the tab clears every entry. That matters here because a night log is a map of when your household is awake and who is in the room. To keep a permanent record, use the printable sheet or log it in DadYolked.
Sources and related tools
Use published guidance, then track your actual nights.
DadYolked keeps sleep, feeds, bottles, pumping, diapers, medicine, growth, and milestones in one local-first record on your iPhone — with Apple Watch, Siri, and widgets for one-handed capture at 3 a.m., and a pediatrician-ready summary when the appointment comes.
Take the pattern to the appointment, not a vague memory.
Night wakings, feeds, diapers, and medicine land in one daily record in DadYolked — so you can answer “how is she sleeping?” with intervals instead of a shrug.