Day 4 of 21
Day 4 — Reduce evening light and screens
Light in the evening tells your body to stay awake — even when you’re tired.
Why this matters
Your body uses light to decide when to be alert and when to shut down.
In the evening, artificial light — especially from screens — delays melatonin release and keeps your system in “day mode.”
You introduced morning light to start your day.
Now you reduce evening light to allow it to end.
What to do today
Stop screen use and reduce bright light 60 minutes before sleep.
- Turn off or limit phones, tablets, and laptops
- Avoid bright overhead lighting
- Use softer, warmer light instead
- Keep your environment visually calm
Rule
Do not replace screens with other stimulation.
Keep the last hour low input.
Supporting guidelines
- Lower screen brightness if you must use devices
- Use night mode / blue light filters (secondary, not primary solution)
- Avoid switching between multiple inputs (TV + phone, etc.)
- Keep the last hour simple and predictable
What to expect
You may not notice a clear difference tonight.
Evening light delays your internal clock subtly.
Reducing it helps your system shift earlier over several days.
Did you:
- reduce screen and bright light in the last hour?
- keep your environment calmer than usual?
If yes, Day 4 is complete.
Tomorrow, you stabilize your environment so your body can fully switch off.