What time does it get dark today?
Dark in
Working out your sky…
Sky by sun angle, not weather
Working out your sky…
Plan another day
DateHow it works
Definitions, the engine, the sources
- Dark is the end of civil twilight: the Sun’s centre 6° below the horizon. After it, USNO says, “artificial illumination is normally required to carry on ordinary outdoor activities.”
- Sunset is when the top of the Sun touches the horizon, with standard refraction. Both are computed in your browser with astronomy-engine 2.1.19.
- Every time is rounded to the nearest minute, as USNO does, and the countdown runs to that rounded minute, so “Dark at 16:55” and 0:00:00 agree.
- Your city is guessed from your device’s time zone. No location prompt, no IP lookup: nothing leaves your browser.
- The painting follows the Sun’s angle (day, low sun, civil, nautical, night) and blends between the two nearest skies once a minute. It says nothing about clouds.
Sources
| Definitions of sunset and civil twilight | U.S. Naval Observatory, Rise, Set, and Twilight Definitions | accessed 2026-11-10 |
| Check of 22 places (80 times: 79 identical, 1 off by a minute) | U.S. Naval Observatory one-day API | accessed 2026-11-10 |
| Computation | astronomy-engine 2.1.19 (MIT) | accessed 2026-11-10 |
| 34,210 cities, zones, names | GeoNames cities15000 + alternate names (CC BY 4.0) | accessed 2026-11-10 |
| US ZIP points and zones | U.S. Census Bureau 2026 Gazetteer (ZCTA) | accessed 2026-11-10 |
Questions
What counts as “dark”?
The end of civil twilight: the moment the Sun’s centre is 6° below the horizon. The U.S. Naval Observatory says that after it “artificial illumination is normally required to carry on ordinary outdoor activities.” That’s the moment we count down to.
How long after sunset does it get dark?
It depends on where you are and the season. On 10 Nov 2026: London 37 min, New York 29, Tokyo 27, Honolulu 23. On 21 Jun 2027: Edinburgh 62 min, Helsinki 112. It’s shorter near the equator and longer far north and in summer.
Is it dark at sunset?
No. At sunset the top of the Sun touches the horizon, and civil twilight follows: there’s still enough light outdoors to walk, run or read a sign. Dark comes when civil twilight ends.
Why is the earliest dark before the shortest day?
Because of the equation of time: solar noon drifts later through December, so evenings start getting lighter before mornings do. In London the earliest dark of 2026 is 16:31, and it holds for five days, Dec 9–13, about a week before the solstice.
Why did it jump an hour?
The clocks changed. On 14 Mar 2027 New York springs forward, and dark moves from 18:28 to 19:29: +61 min, one hour of clock change plus one minute of longer days.
Why doesn’t it get dark in Reykjavík in June?
Around midsummer the Sun never gets 6° below the horizon there; USNO calls it “continuously above the Twilight Limit”. On 21 Jun 2027 the next real dark in Reykjavík is on Jul 24.
How accurate is it?
We checked 80 times against the U.S. Naval Observatory: 79 match to the minute and one is a minute off. Times assume a level horizon and average air; hills, buildings, cloud and city light change what you see.
Updated · U.S. Naval Observatory · astronomy-engine 2.1.19 · GeoNames
You may also like
How dark at 5 pm after the clocks fall back?Type your ZIP to see your sunset before and after Nov 1, your Halloween light window and the earliest sunset of the year.
The sky that night: star map poster
Can I see the northern lights tonight?Type your ZIP or city to see NOAA's aurora forecast for tonight, the Kp you need, when it gets dark, the moon, and which way to look.