Young Blonde Girl Shows Off On Rocks Near The River At Sunset

As sunrise and sunset are calculated from the leading and trailing edges of the Sun, and not the center, the duration of a day time is slightly longer than night time. Further, because the light from the Sun is refracted, the Sun is still visible after it is geometrically below the horizon. The Sun also appears larger on the horizon, an optical illusion, similar to the moon illusion.
Locations north of the Arctic Circle and south of the Antarctic Circle experience no sunset or sunrise at least one day of the year, when the polar day or the polar night persist continuously for 24 hours.