RayDay: Vitamin D Tracker

I built RayDay after years of working indoors left me Vitamin D deficient. The fix wasn't another bottle of pills. It was knowing exactly when the sun was high enough so my body could make Vitamin D the way it always has: naturally, on its own. That's all RayDay does: it tells you your daily sun window, personalized to where you live and your skin type, so you can get Vitamin D the way your body was built to.

FEATURES:

• D-Window Calculator: know exactly when Vitamin D production is possible today and tomorrow
• Live Solar Path: a beautiful animated arc showing the sun's position, sunrise, sunset, and the highlighted D-Window
• 7-Day Forecast: see your D-Window for the coming week
• Skin Type Personalization: your Fitzpatrick type determines how fast you make Vitamin D
• Smart Notifications: get alerted before optimal sun days, plus a heads-up when winter's first D-Window returns
• Atmospheric Data: real-time UV index, cloud cover, humidity, and altitude
• Phase-Aware Design: app colors shift with the time of day. Dawn, daytime, sunset, and night
• Home Screen Widget: a quick glance at your D-Window status
• Works Worldwide: accurate for any latitude, including polar regions

HOW IT WORKS:

RayDay uses NOAA solar position algorithms to calculate the sun's altitude throughout the day. When the sun crosses 35° above the horizon, UVB rays penetrate the atmosphere. That's your D-Window for Vitamin D synthesis.

The app factors in your Fitzpatrick skin type to recommend exposure durations that hit your daily IU goal without overexposure.

Some features require a paid subscription.

DISCLAIMER: RayDay is for educational purposes only. Consult a healthcare professional before changing Vitamin D supplementation or sun exposure habits.

---

LEGAL:
Privacy Policy: http://www.jakubl.com/privacy.html
Terms of Use (EULA): http://www.jakubl.com/terms.html

SUPPORT:
support@jakubl.com
X: @jakublaszczyk