Daylight
–IThe year of daylight
At the equator every day lasts about twelve hours. The farther from it, the deeper the swing: the Earth's axis is tilted 23.4°, so for half the year one hemisphere leans into the Sun.
No curve quite touches twelve hours at the equinoxes. The Sun is a disc, not a point, and the air bends its light over the horizon, so every place gets a few minutes more than half the day.
Daylight from the first to the last edge of the Sun, with standard refraction. Tap the chart to pick a day.
IIEvery latitude, every day
- Polar night: the Sun stays below the horizon all day
- Midnight sun
- Hours of daylight, every two hours; the bold line is the equator, where days stay near twelve hours
- Your place and the chosen day
Tap the chart to move to that latitude and day.
IIIThe Sun's figure-eight
Photograph the Sun at noon by the clock once a day for a year and it traces this figure-eight, the analemma. Up and down is the season. Side to side is the Earth's elliptical orbit and tilted axis, which make the Sun run up to sixteen minutes fast or slow against the clock.
That is why the earliest sunset does not fall on the shortest day.