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True Solar Time for Every Place on Earth

- :sunrise: **What is TimeNow?** TimeNow is a REST API that answers the question civil clocks never could: *what time does the Sun say it is, right here, right now?* - :earth_africa: **Global Coverage** Any GPS coordinate on Earth. Sub-second accuracy using NREL SPA + IERS Earth Orientation Parameters. - :zap: **Zero Auth** Open API. No API keys. No accounts. Just `curl`. - :package: **36 SDKs** Python, JavaScript, Go, Rust, Java, C#, R, Ruby, PHP, Julia, and more.

The Problem

In 1884, the International Meridian Conference split the Earth into 24 time zones — one per hour — to satisfy railroad scheduling. It was a pragmatic hack.

The consequence: civil noon and solar noon diverge by up to 3 hours in places like Kashgar, China (UTC+8), where solar noon actually occurs at 15:10 civil time.

Kashgar, China (39.9°N, 76.0°E)
  Civil time:  12:00  (UTC+8 — same zone as Beijing, 3,700 km east)
  Solar noon:  15:10  (actual moment the Sun crosses the meridian)
  Deviation:   -190 minutes

This is not a quirk. It affects:

  • ~1.4 billion people in China's single-timezone UTC+8
  • Spain and Portugal (westernmost UTC+1, solar time runs ~1 h behind)
  • Western US states at the far edge of their time zones
  • Every Islamic prayer in timezone-misaligned regions

Health Impact

Roenneberg et al. (2012) documented that each hour of civil-solar misalignment ("social jetlag") increases obesity risk by 33%. The EU DST reform stalled in 2019 partly because no tool could quantify the trade-off. TimeNow builds that tool.

Features

Feature Endpoint Description
Solar time GET /solar True local solar time for any coordinate
Timezone reform analysis GET /solar/reform What each DST option costs in solar minutes
Social jetlag score GET /solar/jetlag Roenneberg civil-solar offset + health risk
Prayer times GET /solar/prayer 5 Islamic conventions + Jewish Zmanim
iCal feed GET /solar/ical Subscribe to solar events in your calendar
Almanac GET /solar/almanac Full year of solstices, equinoxes, solar noon
World deviation map GET /world/deviation-map GeoJSON/CSV/JSON global offset grid
Mesh network GET /mesh/* Peer-to-peer solar time sync
Well-Known GET /.well-known/solar-time RFC 8615 machine-readable discovery

Quick Install

git clone https://github.com/koke1997/timenow.git
cd timenow
podman-compose up --build

git clone https://github.com/koke1997/timenow.git
cd timenow
docker compose up --build

Once running, the API is at http://localhost:8090.

# Health check
curl http://localhost:8090/health

# Solar time for London
curl "http://localhost:8090/solar?lat=51.5&lng=-0.1"

Next Steps