How To Help Baby Learn Day from Night: Setting Their Circadian Rhythm
- Caryn Shender
- Aug 3
- 3 min read
As a parent of a newborn, you’ve probably found yourself wondering, *“Why does my baby wake at night and sleep during the day?”* You're not alone — and you're not doing anything wrong. In those early weeks, your baby does not have a set circadian rhythm or internal body clock so they do not know how to tell night from day.
When your baby was in the womb they slept whenever it suited them. Now they are adjusting to life on the outside and rules we have set for them.
But here’s the good news: with some simple strategies, you can gently support your baby’s biological clock — their circadian rhythm — and help guide them toward more restful nights and predictable days.
What Is the Circadian Rhythm?
The circadian rhythm is our body’s internal clock that regulates the sleep-wake cycle. It tells us when to feel sleepy, when to be alert, and when to produce sleep-related hormones like melatonin.
Babies aren’t born with a fully developed circadian rhythm. In fact, for the first 8–10 weeks of life, they don’t really know the difference between day and night. That’s why they wake frequently, nap erratically, and sometimes want to party at 2 a.m.
So how can we help them learn the rhythm of day and night?
How to Help Your Baby Set Their Internal Clock
Your baby’s body clock is shaped by external cues — *and you’re the one who gets to set the stage*. Here’s how:
☀️ **Daytime Strategy**
* **Start the day at the same time each morning.** Consistency matters!
* **Expose baby to natural light.** Open the curtains, go for a walk, or feed near a sunny window.
* **Keep the environment active.** Don’t tiptoe — household noise and movement help signal it’s daytime.
* **Wake baby to feed during the day.** Ensure they’re getting enough calories in the daylight hours.
🌙 **Nighttime Strategy**
* **Dim the lights.** Keep things dark and calm after sunset.
* **Create a bedtime routine.** Bath, book, feed, crib — a predictable flow helps wind things down.
* **Limit stimulation.** Save play and chatter for the day; at night, keep things quiet and soothing.
* **Use white noise.** This can signal sleep and mask household sounds.
The Role of Melatonin (and Why Timing Matters)
Melatonin is the hormone that helps us fall asleep — but babies don’t begin producing it on their own until around 8 weeks. Until then, they rely on you to help set the scene.
One fun fact? Breast milk changes composition throughout the day. Evening milk actually contains more melatonin — so feeding at the breast (or offering pumped milk from evening hours) may help signal nighttime.
Avoiding Common Sleep Disruptors
Even with the best routines, disruptions happen. These are some common culprits:
Overtiredness from skipped naps
Developmental leaps
Illness or teething
Bright screens or lights before bed
Travel or time zone changes
When things go sideways, just return to your daytime/nighttime cues — your baby’s body will get the message.
Safe Sleep Always Comes First
While we work on sleep, safety is always the top priority. Remember the ABCs:
* **A**lone
* **B**ack
* **C**rib
That means:
* No loose blankets, pillows, or bumpers
* No swings, car seats, or inclined sleepers for routine sleep
* No co-sleeping — room-sharing is safest
* Rule of Thumb: If it has straps, it’s not safe for sleep
Swaddles and pacifiers are okay — just be sure the pacifier is not connected to the clothing while baby is sleeping, and stop swaddling when baby shows signs of rolling.
Final Thoughts
Helping your newborn develop a circadian rhythm doesn’t happen overnight — but with the right tools and a little patience, your baby can learn the difference between day and night, setting the foundation for healthier, more predictable sleep.
WHEN TO REACH OUT FOR HELP
Sleep struggles can be overwhelming and frustrating. You are not alone. If you feel like you have tried everything, we can help.
If your child (age 0-6 years old) is struggling with sleep, schedule your FREE 15-minute Sleep Consultation call to talk through your child’s sleep challenges, your goals, and what Sleep Tight Tonight programs offer, so that we can make a plan for change together.
Caryn is a proud mom of two, certified pediatric sleep consultant, safe sleep ambassador, and author of My Scar is Beautiful. She is passionate about and committed to helping families turn sleepless nights into easy, peaceful nights and sweet dreams. Being a parent is hard. Being an exhausted parent is next to impossible. Together, we’ll make sleep easy.
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