If Dec. 21st is the shortest day of the year, how come the days & nights at the equator stay the same?

Answer 1

On Dec 21st or 22nd,the northern hemisphere will have the shortest day and the southern hemisphere will have its longest day(particularly between the tropic of cancer and the tropic of capricon;Beyond that, day and night extend upto six months).So in between there should be a latitude where the day and night should be equal.That is the zero degree latitude i.e. equator.

Answer 2

Because only north of the Equator is it true that 12/21 has the least daylight. South of the Equator, that date has the most.

Answer 3

And in between, they don't change.