SunSpan

SunSpan — A Year of Daylight on One Screen

SunSpan renders an entire year of sunrise, sunset, and twilight as a single chart. Each day is a vertical band shaded from astronomical night through nautical and civil twilight into full daylight, so the seasonal curve, the solstices, the equinoxes, and
effects like white nights and polar day are visible at a glance. Tap or drag across the chart to select any day and see its sunrise, sunset, daylight length, and twilight phase times in a detail bubble.

Features
- Full-year daylight chart for any location, any year from 1900 to 2100
- Eight-stop twilight gradient: night, astronomical, nautical, civil, day
- Tap or drag any day to inspect sunrise, sunset, daylight length, and twilight phase times
- DST transitions marked on the chart
- Location picker via satellite map, or automatic from device GPS
- Time zone resolved automatically from the selected coordinates
- Localized in English, Spanish, German, and Ukrainian

Privacy
No accounts, no analytics, no ads. Location is used only on-device to compute solar geometry and never leaves the device.