Day and Night World Map
This map shows the current distribution of daylight and darkness across the world. It updates every second based on the real-time position of the Sun.
How to Read the Map
The bright area represents the portion of the Earth currently receiving sunlight. The dark area is in night. The curved line between them is called the terminator or day/night boundary.
- The map updates every second using your local clock.
- The Sun's exact position is calculated from astronomical formulas (celestial navigation).
- The boundary shifts westward as the Earth rotates (~15° per hour).
- The tilt of the boundary changes with the seasons due to the Earth's axial tilt of 23.5°.
- The map shows four zones: full daylight, civil twilight (Sun 0–6° below the horizon), nautical twilight (6–12°), astronomical twilight (12–18°), and full night.
About the Day/Night Terminator
At any given moment, exactly half of the Earth faces the Sun and is in daylight, while the other half is in darkness. The terminator line — the boundary between day and night — moves at about 1,670 km/h at the equator, matching the Earth's rotation speed.
During the equinoxes (around March 20 and September 22), the terminator runs from pole to pole and every location on Earth gets roughly 12 hours of daylight. During the solstices, the tilt is most pronounced: the Arctic has continuous daylight in June, while Antarctica is in perpetual night.
Frequently Asked Questions
What is the terminator line?
The terminator is the moving boundary between the sunlit and dark sides of the Earth. It travels westward at the speed of Earth's rotation.
Why does the shape of the boundary change?
Because the Earth's axis is tilted at 23.5°. As Earth orbits the Sun, this tilt causes the terminator to shift between solstice extremes throughout the year.
Is this map real-time?
Yes. The Sun's position is recalculated every second using your device's clock and published astronomical formulas.
What are the twilight zones?
Twilight occurs when the Sun is below the horizon but still illuminates the atmosphere. Civil twilight (0–6° below) has enough light for most outdoor activities. Nautical twilight (6–12°) lets sailors see the horizon. Astronomical twilight (12–18°) is when the sky is almost fully dark.
Related Date & Time Tools
- Hours From Now Calculator — What time will it be?
- AM/PM to Military Time — Convert 12-hour to 24-hour time.
- Military Time Converter — Convert 24-hour to AM/PM.
- Epoch Converter — Convert Unix timestamps to dates.
References
- Henning Umland — Celestial Navigation Calculations
- Sunlight World Map Gadget — GitHub.
- World map image — Licensed under CC BY-SA 3.0 (Wikimedia Commons).
