Sundial tracks the daylight you're actually getting, and gently nudges you back into rhythm.
Join the waitlistShipping fall 2026 · Priority for early signups
No streaks, no scores, no leaderboard. Sundial tells you how much daylight you've had and when to get more. Then it leaves you alone.
Your body clock needs bright, natural light to hold its rhythm. Most of us spend the day at a hundredth of what it expects.
A quiet sensor, smaller than an AirPod. It clips to a bag strap or wristband and reads real lux — actual brightness, not a phone's guess from inside your pocket.
Every Sunday morning: your light week in three sentences and one suggestion. No graphs to decode. No score to protect.
Timed to your first circadian dip, not a fixed schedule. One step outside is the entire intervention. It's the most-studied circadian fix there is, and it's free.
"Three weeks in, I stopped needing coffee at 2pm. That's the whole review."Early user, Denver
First batch ships fall 2026. Waitlist gets first pick, and our Sunday letter on light.
Join the waitlist