Lenghts of day and night

How long do day and night last? Day and night "arise" from the rotation of the earth around its own axis, whereby the earth rotates around its own axis once every 24 hours. Therefore, day and night should last exactly the same amount of time (twelve hours). However, day and night are not the same length at every location on Earth. This can be illustrated with the Sun, Earth, Moon model. The students observe that exactly at the equator day and night always last exactly twelve hours, while in other parts of the earth the length of day and night are different.