Summer Solstice was last Friday and now the days will get shorter and the nights longer in our slow progressive darkening until Dec. 21. Then things will begin to lighten up again.
No one could have noticed it of course, unless they were paying very, very careful attention. Friday literally had an additional second of light compared to the day before (and since then we’ve lost almost a minute!). However, many of us knew it was the Summer Solstice because every year, this inflection point of light and darkness is printed in the calendar.
It is unusual that a day on the calendar marks an actual specific astrological event. Each day of course represents a single revolution of the Earth on its axis. Each year is another orbit of Earth around the sun. But there’s no event or happening at midnight when we divide day from day. (In fact, wouldn’t it makes more intuitive sense to divide the days at sunset or sunrise? Has anyone ever looked at their watch at 12:01 a.m. and said “Ah, the start of a new day!”) In terms of counting years, there is nothing distinct about the transition between Dec. 31 and Jan. 1 beside the fact that humans have chosen to make this the moment when one year ends and another begins and so an excuse for a party. The way we divide up the year is a motley patchwork to satisfy our need for order against the orbits and rotations that create days and seasons.
Our calendar is a great collective work of human inquiry and ingenuity. It is now the world-wide standard tool for communicating about future and past events which can be used by billions of individuals with stunning precision to know exactly when events have and will occur. Yet for all its capacity and success, our calendar is a hodgepodge of antiquated religious and mathematical ideas we would reject immediately if we weren’t dependent on them to know when our guest were going to arrive. Our week for example is a pagan prayer schedule starting with a long weekend of Roman deities (beginning on Saturday): Saturn, Sun, and Moon, followed by the Norse-gods work-week: Tiu (war), Wodin (or “Odin” — god of wisdom), Thor (Odin’s son — god of thunder), Frigga (Odin’s wife — goddess of marriage and fertility). Even the most committed monotheists are still invoking those ancient myths as we plan our weeks.
The division of those deity-days into 24 units is an artifact of ancient Egyptian time accounting. The further division of those hours into 60 minutes and then each minute into 60 seconds was brought to you by Babylonian mathematicians. (You can thank them for the strange math of your microwave where 2:00 = 120.)
It was not a smooth process to arrive at our mishmash calendar. At various times in human history, misunderstanding and mismanagement created unworkable discrepancies between the calendar and what it was supposed to describe. For example, when Julius Caesar took control of the Roman Empire, their calendar was about three months out of synch with the seasons. In response, Caesar, as only an imperial ruler can do, reworked and rebooted the system. The result was that the “year” 46 BCE lasted a whopping 445 days.
Our calendar continues to evolve but now requires much more subtle adjustments. Some of the adjustments we don’t even notice. For example, since 1967 we’ve needed to add about 8 seconds per decade to adjust for a new way of measuring the length of a second.
We humans built this strange, cumbersome multi-cultural patchwork tool over thousands of years from the most compelling ideas of the ancient world. It is far from perfect, but it is the best tool we’ve got to know when a thing happened or might happen, or to appreciate the days as the light is withdrawn and returns.