Winter solstice one must be able to observe a change in azimuth or elevation less than or equal to about 1/60 of the angular diameter of the sun. Observing that it occurred within a two-day period is easier, requiring an observation precision of only about 1/16 of the angular diameter of the sun. Thus, many observations are of the day of the solstice rather than the instant. This is often done by observing the sunrise and sunset or using an astronomically aligned instrument that allows a ray of light to be cast on a certain point around that time. Length of day
Winter solstice Syrian god who was later adopted as the chief god of the Roman Empire under Emperor Aurelian. His holiday is traditionally celebrated on December 25, as are several gods associated with the winter solstice in many pagan traditions. It has been speculated to be the reason behind Christmas' proximity to the solstice. In East Asia, the winter solstice has been celebrated as one of the Twenty-four Solar Terms, called "Dongzhi" in Chinese. In Japan, in order not to catch cold in the winter, there is a custom to soak oneself in the yuzu hot bath ( = Yuzuyu). Although the