Day and night map

How to use it

When you open the page you’ll see the current moment, which updates every minute while the page is in view. Use the date and the slider (in your time) to jump to any other moment, or the buttons to go to this year’s solstices and equinoxes. “Back to now” puts it back on live.

Tap anywhere on the map to see the local time there, whether it’s daytime or which twilight it’s in, and when the sun rises and sets that day. Below the map you’ll find the same for twelve cities around the world. The top-left switch flips between the globe and a flat map.

The line between day and night

Half of Earth is always lit by the sun. The edge between the day half and the night half is called the terminator, and on the map it’s the golden line: along it, the sun is rising or setting. As Earth turns, the line moves west 15° of longitude an hour; at the equator, that’s about 1,040 mph.

The gray bands are civil, nautical and astronomical twilight, with the sun up to 6°, 12° and 18° below the horizon. Each 6° band is about 415 miles wide, so it’s about 1,240 miles from sunset to full darkness.

Why the line changes shape with the seasons

At the equinoxes (in 2026, on March 20, 2026 and September 23, 2026) the sun is directly over the equator and the line runs from pole to pole: day and night are equally long everywhere. At the June solstice (June 21, 2026, at 8:25 AM UTC) the sun is directly over the Tropic of Cancer, at 23.44° north: the whole Arctic Circle is in daylight and the whole Antarctic Circle in darkness. At the December solstice (December 21, 2026) it’s the other way around.

That’s why, on the flat map, night forms a curve in summer and winter and almost a straight line in spring and fall. Try it with the solstice and equinox buttons.

The sun and the moon overhead

The yellow circle marks the spot on Earth where the sun is directly overhead at that moment (90° up). It always stays between the two tropics and goes around the world once a day. The purple circle is the same for the moon, as seen from Earth’s center.

How it’s calculated

We work out the sun’s position with Astronomy Engine (accurate to one arcminute) and, from it, the point where the sun is overhead. The night areas are spherical caps around the opposite point: where the sun is more than 0.83° below the horizon (allowing for refraction and its radius, as sunrise and sunset tables do), and more than 6°, 12° and 18° below. We checked them point by point against the sun’s elevation worked out for each spot: they’re less than a mile apart. Mountains and elevation aren’t taken into account.

To save battery, the map is recalculated only once a minute, right as the minute changes, and it stops while the tab is hidden.