For as long as I remember, I have had a mild but persistent curiosity about New Years Day. Why does the year start on January 1? It has to start somewhere, I guess, but any day chosen should have an explanation. There are probably people here who know, but the times I have looked into it, I have received explanations which were less than convincing.

Some people point to the approximate proximity with the winter solstice. That might be, but January 1 is 11 days off from the solstice. This could be explained by centuries of calendar slop, but that seems unlikely especially since the calendar was moved twenty days in the mid 18th century to fix some of its slop. Why not this one too?

Some point out that Janus is the Roman god with two faces, one looking forward and the other looking back so the month named after him would appropriately be the first of the year. That sounds poetic and all, but it seems that naming January after Janus is really the effect of it being the first month and not the cause. If you think about it, even naming January 1, January 1 is a choice made by somebody based on something. Any day could have been named January 1. (I’ve always considered October 1, 1953 as the first of all days.)

A couple of years ago, I was listening to Earth and Sky and they reported that day as the one with the latest sunrise. After the Winter Solstice, though the days start getting longer, the Sun continues to rise later. This is because at this time of the year Earth is closest to the sun and is moving faster than at other times so it takes the Earth’s spin longer to catch up to where the Sun is in relationship to it. (This is because of our elliptical orbit and is also the reason why the pattern of the Sun at the same time of day throughout the year is a figure eight.) This struck me as the real reason why January 1 is considered the first day of the year: Those ancient astronomers/calendar makers observed that on that day the Sun rose its latest and started rising earlier from there. This is a significant observation of the natural phenomena and a natural starting time for the year.