Where did the change begin?
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.
Labs / Geography / Day, Night & Time Zones
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.
Why it matters
Why explore this?
Geography explains how places, people, and Earth systems affect one another. This model lets you change one factor and watch its effects spread across space.
Explore
Try the model
12:00 UTClocal London 12:00daylight hover globezone —
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
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?
Explain
Make sense of what happened
Connect the pattern to place: identify where the change begins, where its effects appear, and which process links those locations.
Check
Before you leave
What spatial pattern appeared?
Which process connects the cause and effect?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.