They noticed that in some seasons the days were very long; and as a result, in those days, they could use more sunlight. The belief arose that the light and brightness of the sun were a symbol of goodness and agreement; and that they were in battle with the darkness of the night. Ancient people, including Aryans and Indo-Europeans, found that the shortest days are the last days of autumn and the first night of winter; and immediately after that, the days gradually get longer and the nights shorter. So they called this night, “The night of sun’s birth (Mehr)”; and made it the beginning of the year.