January Sky Notes

The ancient Germanic peoples of Britain and Northern Europe celebrated the turning of the year at the Solstices, which they could track by following the path of the Sun. This is probably the reason for building stone circles and henges such as Stonehenge. Despite the celebrations by modern-day “druids” at the Summer Solstice, it is most likely that these monuments were actually built to record and celebrate the Winter Solstice on 21st December, when the Sun reaches its lowest point in the sky. Rituals, sacrifices, and celebrations would have been held in order to ensure the return of the life-giving Sun for the next year. Amongst these rituals were the dressing (or decorating) of trees, bringing greenery into the home, keeping Yule logs burning throughout the dark times and feasting on calorie-rich foods to sustain oneself through the Winter. It was in order to mask these celebrations, by subverting them to their own cause, that the later Christians chose December to contain the festival of Christmas. But even today, most of the traditions associated with the holiday have their roots in pagan mythology.

The 365-day year continued into the early Middle Ages where it caused many arguments, often labelled as heresies by the Catholic Church, as it proved very difficult to establish the exact date of Easter (the most important Christian festival) from year to year. Different churches and different countries, even different cities all used their own formula for calculating the date, none of which agreed with each other. This was eventually standardized, but it took well over 100 years to reach any kind of agreement. Even then dissenters such as the Eastern Orthodox Church used their own, alternative calculations well into the modern age. 

The consensus was reached by agreeing to measure the year, not by the Sun or the Moon, but by the stars, beginning at the First Point of Aries at the Vernal (Spring) Equinox (The use of this date is why our Tax Year starts at the beginning of April) which gives rise to a year of 365¼ days, the actual time (approximately: we still insert leap days and leap seconds from time to time in order to maintain the accuracy of the calendar) it takes for the Earth to make one complete orbit of the Sun. The ¼ days are saved up in order to make an extra day every four years – a Leap Year.

Another interesting attempt to alter the calendar was made during the period of Revolutionary France. Having changed all the old Royal or Imperial measures to the new Metric system the Revolutionary Council attempted to do the same with the calendar. They proposed a year that had just 10 metric months, each being one tenth of a year. Of course this meant that each month was to be 36½ days long, which was too unwieldy, even for the French. So a compromise was reached where alternate months had first 35 days followed by a month of 36 days.

Nowadays, the exact length of the year is measured by the vibrations of Caesium atoms in an atomic clock, completely invisible to human perception and rather less glamorous than the stories of the past.