Astronomy & Weather Tools
Free calculators powered by astronomical algorithms — everything runs locally in your browser. No data sent, no account needed.
🌅 Twilight & Golden Hour
Find exact times for civil, nautical, and astronomical twilight — plus golden hour and blue hour windows.
Perfect for photographers, astronomers, and sailors.
Open Calculator →📍 Location Finder
Find your exact GPS coordinates and timezone. Useful for configuring your KairosEye watchface or any location-based tool.
Interactive map with search by city name.
Open Tool →🌙 Moon Phase
Current lunar phase, illumination percentage, moonrise/moonset times, and upcoming major phases.
Know when the next full moon is at a glance.
Open Calculator →🌬 Beaufort Scale Converter
Convert wind speed (km/h, mph, knots, m/s) to Beaufort force number. See sea and land conditions for each level.
From calm to hurricane force — all 13 levels.
Open Converter →☀️ UV Index Estimator
Estimate current and peak UV levels based on sun angle, altitude, cloud cover, and surface type.
Daily UV profile with protection advice.
Open Estimator →😴 Sleep Cycle Calculator
Find the best time to go to bed or wake up based on 90-minute sleep cycles. Optional sunrise alignment.
Wake up refreshed, not groggy.
Open Calculator →🛰 GPS Coordinate Converter
Convert between Decimal, DMS (Degrees Minutes Seconds), and UTM formats. Open in Google Maps.
Decimal ↔ DMS ↔ UTM in one click.
Open Converter →🗓 Public Holidays
Find public holidays for any country. Capital timezone, 12-month calendar view, and ready-to-copy MMDD format for your KairosEye watchface.
Open Tool →All calculations run locally in your browser. No account needed, no data stored.