Sun, Moon & Space

Solar and lunar timing for any city in our index. Computed from each city's coordinates using the standard NOAA solar position algorithm — the same maths used by professional almanacs and aviation software.

Today's sun, at three latitudes

The same date, three different planets — at least if you go by daylight. This is what latitude does to your day:

Find your own city in the World Clock — every page lists today's civil dawn, sunrise, solar noon, sunset, civil dusk, and total day length.

How we compute this

Sunrise and sunset are not arbitrary. They depend on the date, the observer's latitude and longitude, and the apparent altitude of the sun's centre at the moment its upper edge crosses the horizon — conventionally −0.833°, accounting for atmospheric refraction and the sun's angular radius. The full algorithm involves the planet's mean anomaly, the ecliptic longitude, the sun's declination, and the hour angle. We implement the version published by Jean Meeus in Astronomical Algorithms (1991), which agrees with the US Naval Observatory's tables to within about a minute for most latitudes.

Civil twilight (sun 6° below the horizon) defines the period when there's still useful natural light without artificial sources. We compute that too, on every city page.

Coming next

• Moonrise, moonset, and current lunar phase per city
• Equinox and solstice dates for the current year
• Visible-planet rise/set times
• ISS pass predictions