Free sun exposure timer for morning sunlight and vitamin D optimization. 10–30 minute countdown for safe, timed outdoor sunlight sessions.
Andrew Huberman's protocol recommends 5–10 minutes of outdoor sunlight within 30–60 minutes of waking on clear days, 15–20 minutes on partly cloudy days, and 20–30 minutes on overcast days. Morning sunlight anchors your circadian rhythm, improving sleep quality at night.
Bright outdoor light in the first 1–2 hours after waking sets a cortisol peak that regulates your alertness-sleep cycle. This morning light signal, processed through specialized retinal cells (ipRGCs), suppresses melatonin during the day and ensures it rises at the right time in the evening.
Vitamin D synthesis depends on skin tone, latitude, season, and time of day. Generally: 10–30 minutes of midday sun on face and arms for lighter skin tones; longer for darker skin. Morning sunlight is great for circadian benefits but less effective for vitamin D (UV-B is lower at low sun angles).
No — standard glass filters UV-B (needed for vitamin D) and significantly reduces the lux intensity that reaches your eyes for circadian benefits. Outdoor sunlight is 10,000+ lux; indoor by a window is 200–500 lux. Open windows or go outside. The timer only helps if you're actually outdoors.
Don't look directly at the sun — only look toward it (in the general direction) while blinking naturally. Looking near (not at) the sun on the horizon is safe and effective. Retinal ganglion cells sensitive to circadian signals are activated by the broad sky light, not the direct solar disk.