Light in the morning is the main signal that sets your body clock. It tells the brain when the day started, which shifts when it makes you sleepy that night. Evidence: solid It also lifts the morning cortisol rise, which is the useful, wake-up kind. Evidence: decent
The clock mechanism is solid science. The specific "ten minutes outside" dose is a practical rule of thumb, not a tested prescription. Outdoor light is many times brighter than indoor light even on a grey day, so outside matters more than duration. Evidence: decent
Same theme: Morning
Morning
Nap short or not at all
If you nap, ten to twenty minutes, early afternoon, alarm set. Longer or later costs you tonight.
20 minEvidence: decent
Morning
Ten screen-free minutes after waking
No phone until you've been up ten minutes. Water, light, a window, then the phone.
10 minEvidence: worth trying