Day and Night Map
See where on Earth it is day, twilight and night right now or at any time, with the points where the sun and moon are overhead, and check the light at any place.
Working out where it is day and night…
How to read the day and night map
- See the shading. The darker the band, the deeper the night: past sunset, then civil, nautical and astronomical twilight, then full night.
- Find the sun and moon. Markers show where each is directly overhead.
- Change the time. Use the date box, the hour buttons or the slider to move up to 12 hours either way.
- Check a place. Search a place or click the map to see whether it is day, twilight or night there.
Why look at a day and night map
Calling abroad
Is it daytime where they are?
Ham radio
The grey line along the terminator is prized for long-distance contacts.
Photography
See where golden hour is happening now.
Teaching seasons
Watch the night cap the poles at the solstices.
Flights
See whether you will land in daylight.
Astronomy
Where it is dark enough for the stars.
How the map is calculated
The point where the sun is overhead comes from NOAA's solar position equations (declination and equation of time). The sun's altitude anywhere follows from that point, and the map shades each 1° column of longitude where the altitude is below −0.833° (sunset, with refraction), −6°, −12° and −18° (the ends of civil, nautical and astronomical twilight).
The moon's position comes from Paul Schlyter's method for planetary positions with the main lunar perturbations.
The web map stops at about 85° latitude, so the poles are not drawn. Everything is calculated in your browser.
Frequently asked questions
What is the grey line?
The band of twilight along the boundary between day and night.
Why is half the Earth not exactly lit?
Refraction and the sun's width extend daylight slightly, and twilight adds a broad band on the night side.
Why is the line curved?
It is a great circle on the globe; the flat map's projection curves it, most of all near the solstices.
Can I see a past or future date?
Yes, enter any date and time.
Is the moon shown at the right place?
It marks where the moon is overhead, from a method accurate to about a minute of arc.
Related tools
Sun Position Calculator
Pick a place, date and time and get the sun's elevation and compass direction, plus sunrise, sunset, solar noon and day length in local time, with a chart of the sun's path that day.
NOAA solar calculator equations (Meeus, Astronomical Algorithms)
Distance to Horizon Calculator
Enter your eye height and get how far away the horizon is, with and without standard atmospheric refraction, plus how far you can see a tall object and how much of it the curve hides.
Spherical-Earth horizon formula d = √(2Rh + h²), refraction R′ = 7R/6 (A. T. Young)
Sunrise Sunset Calculator
Get sunrise, sunset, dawn, dusk, solar noon and day length for every day of any month at any place, in its local time with daylight saving, and download the table.
NOAA solar calculation equations; IANA tz database
Time Zone Finder
Type any address or use your location and get its IANA time zone, current local time, UTC offset, whether daylight saving time is in effect, and the date of the next clock change.
Time zone from Open-Meteo; rules from the IANA tz database in your browser
Time Difference Calculator
Compare the time in several cities at once, see how many hours ahead or behind each one is, convert a time between them and find the hours that suit everyone.
IANA tz database in your browser; Open-Meteo time zone lookup
US Time Zone Map
A map of US time zones with the current time in each, their abbreviations and UTC offsets, and which areas skip daylight saving time — hover any area for its local clock.
timezone-boundary-builder (OpenStreetMap); IANA tz database