About Daylight Hours

Daylight Hours is a free web tool that shows you the sunrise time, sunset time and length of the day for any location on Earth — today, or on any date you choose. There is no sign-up, no paywall and no limit on how often you can use it.

The site is an independent project, run by a small team of people who are simply fascinated by how the rhythm of light changes through the year. It is published in two languages: English at daylighthours.app and Danish at dagenslaengde.dk.

What you can do here

Beyond the basic sunrise and sunset times, the site lets you explore the sun and moon in depth:

  • Day length in hours and minutes for any date and place
  • Sunrise, sunset, solar noon, and the civil, nautical and astronomical twilight times
  • A year-long chart of how the day length rises and falls
  • An interactive solar calendar
  • City-to-city comparison of daylight
  • Moon phases, full and new moons, and lunar eclipses

How we calculate the times

All of the sun and moon figures on this site are computed astronomically in your browser using the well-established SunCalc library. We do not call an external weather or astronomy API for the sun data — the maths runs locally from your coordinates and the date you pick. This means the results are accurate to the minute for any latitude and longitude in the world, and they keep working even on a slow connection.

Because the calculation is purely geometric, the times we show are for a flat, unobstructed horizon. Your real-world sunrise or sunset can differ by a few minutes if you are surrounded by mountains, tall buildings or hills, and atmospheric refraction can add a couple of minutes at each end of the day.

Get in touch

Spotted something wrong, or have an idea for the site? We would genuinely like to hear it — head to our contact page and send us a message. You can also read how we handle data in our privacy policy.