About Sunset Tracker
Sunrise, sunset, golden hour and twilight times for 733 cities, calculated rather than copied, and checked against the US Naval Observatory.
What this is
Sunset Tracker answers one question well: what time is sunset here, and what happens to the light around it. Every city page carries today’s times, a calendar for this month and next, the compass bearing the sun sets on, the year of daylight in a single chart, and the moon.
It started as a small tool for tracking sunset across capital cities. That version rendered everything in the browser and covered a fixed list. This one computes each page on the server, covers 733 cities in 243 countries, and rebuilds every page daily so the times on it are the times for that day.
Where the numbers come from
City names, coordinates, elevations and time zones come from GeoNames, used under CC BY 4.0. Cloud cover and visibility for the sunset-conditions widget come from Open-Meteo, requested by your browser only when you open a page that shows it.
The astronomy is ours. Sun positions use the NOAA solar position algorithm, following Meeus, with atmospheric refraction taken at −0.833° for the sun’s upper limb. Moon phase instants use Meeus chapter 49. Nothing is scraped from another site.
How accurate
Every event is validated against the US Naval Observatory across fifteen locations from Ushuaia at 54.8°S to Longyearbyen at 78.2°N, on both solstices, both equinoxes, a daylight-saving changeover and a half-hour time zone. Forty-six checks, all inside 34 seconds, most inside ten. Moon phase instants match USNO to the minute.
That is worth stating plainly because several widely used sunset sites are about ninety seconds out on sunrise and sunset. They subtract the sun’s apparent radius from an altitude that already accounts for it, which stretches the day by roughly three minutes. Their solar noon and twilight figures are correct; the sunrise and sunset ones are not.
Two honest limits. Times assume a sea-level horizon, which is what USNO publishes and what makes our figures comparable to everyone else’s; elevation is shown separately and its effect described on the pages where it matters. And refraction assumes a standard atmosphere — real refraction varies with temperature and pressure by tens of seconds near the horizon, which is a floor on the accuracy of any published sunset time.
Who writes this
Cost and tracking
Free, with no account, no advertising and no analytics. The site sets no cookies and loads no third-party fonts or scripts. See the privacy page for the detail.