|MadSci Network: Earth Sciences|
The question seems to indicate that you have learned that the sun is overhead at the equator on two days of each year. On those days, the daylight period is exactly 12 hours, and the daylight varies on other days from a little more than to a little less than 12 hours, but the variability is much less than at areas nearer the poles. [Moderator note: Here are some links to related articles in our archives: Length of Day What is a Day? Day and Earth's Rotation Apparent Sun Movement When I lived in Kinshasa,Zaire,Africa the length of day and times of sunrise and sunset did not vary noticeably unless you kept track with a watch, maybe plus or minus 15 minutes over the course of a year. The latitude is about 4 degrees south of the Equator.]
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