Labs / Geography
Day, Night & Time Zones
This is one moment on Earth, lit from a single direction. Press play to let the hours run, or drag the time slider yourself, and watch the shadow line — the terminator — crawl across the globe while every city's clock ticks with it. Change the date to tilt the shadow with the seasons, and click a city to follow its local time.
12:00 UTClocal London 12:00daylight hover globezone —
What to try
- When it is midday in London, what time is it in Tokyo and in Los Angeles — and which of them is still in darkness?
- Jump to the June solstice and drag the globe upward to look down on the Arctic. Why does Longyearbyen never fall into night?
- Hover over the equator and then over 60° latitude. How much does the length of daylight change between them in December versus June?
- The terminator is a straight line at the equinoxes but a slanted curve at the solstices. What is tilting, and why does that give the poles a whole day of light or dark?
- Click a mid-ocean spot to read its UTC offset. Why do neighbouring wedges always differ by exactly one hour, and where does the date itself change?