How long are days and nights?

Answer 1

Actually, it depends on the season and your location.

In the tropics, day and night are closer to 12-hour periods (sunrise to sunset and sunset to sunrise). But only at the equator is it always virtually an even split.

Outside the tropics we have summer, with much longer days, and winter, with much shorter days. When one hemisphere, north or south, is tilted toward the Sun, it receives more than 12 hours of daylight per calendar day. The other hemisphere is receiving less than 12 hours of daylight. Only at the equinoxes (spring and fall) are days and nights roughly 12 hours each. This is when the Sun is directly overhead at the Equator.

Toward the poles, the disparity becomes greater, with much longer days in the summer and much longer nights in the winter. North of the Arctic circle or south of the Antarctic circle, areas will receive at least one day a year with 24 hours of sun, and correspondingly at least one day a year of no sunlight at all. Moving poleward, the number of days (length of periods) increases, until you reach the poles, where there is one 6-month period of daylight and one 6-month period of night.

Example:

Longest and shortest days in Havana, Cuba : 13.6 hrs (June) / 10.7 hours (Dec.)

Longest and shortest days in Boston, MA: 15.3 hours (June) / 9.1 hours (Dec.)