In antiquity the beginning of the year was reckoned from the start of spring, called the vernal [[equinox]]. The vernal equinox and the autumnal equinox are the two days each year when day and night are equal in length. The constellation through which the sun is passing at the time of vernal equinox changes slowly with the centuries, and therefore the stars associated with the season of spring also change slowly. | In antiquity the beginning of the year was reckoned from the start of spring, called the vernal [[equinox]]. The vernal equinox and the autumnal equinox are the two days each year when day and night are equal in length. The constellation through which the sun is passing at the time of vernal equinox changes slowly with the centuries, and therefore the stars associated with the season of spring also change slowly. |