Mentis- Get daylight within the first hour after waking: curtain open, balcony, door, a short walk.
- Do it before the phone.
- Morning light is the main signal that sets your body clock, and it makes you sleepy on time at night.
- In Mentis: "On My Feet, Then The Light" and "Let The Light In Before The Alarm", from the Sleep plan.
How do you do it?
- At your set wake time: feet on the floor.
- Light first. Curtain open, or step out to the door, balcony or terrace. If you can, drink your water or chai there.
- One stretch and a glass of water. Then the phone.
- Optional upgrade: leave the curtain slightly open at night so the room brightens before the alarm. That's "Let The Light In Before The Alarm".
Why does morning light help you sleep at night?
Your body clock runs a little longer than 24 hours, so it needs resetting every day, and light is the main way it gets reset. Light in the morning moves your clock earlier, which means you get sleepy earlier at night. Light late at night does the opposite (Blume et al., 2019).
This is easy to underestimate because indoor light feels bright. It isn't, to your body clock. Outdoor daylight, even on a cloudy day, is many times brighter than a lit room. In one well-known study, a week of camping with only natural light shifted people's body clocks about two hours earlier, and made the clock line up with sunrise and sunset (Wright et al., 2013).
When should you use it?
- Every morning while you're resetting your sleep schedule, along with a fixed wake time.
- Especially after a late night, a weekend lie-in or travel.
- In the afternoon, too: the Work plan's "Afternoon Daylight, Not The Fourth Chai" uses a few minutes outside to beat the slump.
Where is it in the Mentis app?
It's part of chapter 2 of the Sleep plan, "A time I wake up", where it's the second keystone habit, "On My Feet, Then The Light". Your morning check-in asks about it, and sometimes how many minutes of daylight you got.
Frequently asked questions
How much morning light do I need?
A few minutes outdoors or at an open window is a good start. Longer is better on cloudy days. Outdoor light, even overcast, is many times brighter than indoor lighting.
Does light through a window count?
An open window or door is best. Light through closed glass is weaker but still better than none. On a dark, rainy or smoky morning, standing at the open window counts.
Can I just use my phone screen?
No. Phone screens are far too dim to set your body clock, and checking the phone first thing tends to keep you in bed.
What time should I get morning light?
As soon as you can after your set wake time, ideally within the first hour.