Solstice Tracker

Application is live at: Solstice Tracker

Single-page React app that compares today's daylight to the winter solstice for a handful of Norwegian cities. Sunrise/sunset times are calculated with the excellent suncalc library for high precision.

How it works

• Pick a city with the number keys (1–8) or tap the buttons on touch devices.
• The app shows how much longer today is than December 21, along with sunrise and sunset for the selected city.
• A small countdown tracks time left until the next winter solstice, and the sun bar fills as we move toward midsummer.

Running it

pnpm install
pnpm dev    # start Vite dev server
pnpm build  # type-check + production build
pnpm test   # run tests

Notes

• City list and UI live in src/App.tsx.
• Daylight math is handled by src/utils/getSunTimes.ts and src/utils/daylightDifference.ts.
• The calculations rely on the suncalc library to provide high-accuracy solar positioning and timing, which corrects for factors like the Equation of Time.