This post is part of a series, Reading Time at HSNY, written by our librarian, Miranda Marraccini.

Maybe you’ll be watching the time ball drop in Times Square on December 31, waiting for the opening notes of “Auld Lang Syne” to start playing over the kissing, crowds, and confetti. Or maybe you’ll be asleep on the sofa, blissfully unaware of the minutes passing as the year turns passively over into 2024.

Whether or not you’re personally focused on the promise that a new year brings, there’s no denying that it’s a moment when people all over the world are uniquely fixated on the time–when, exactly, does something end and something new begin? How do we define what a year is? In this post I’ll focus on calendars: why they are the way they are, how they’ve captivated and frustrated people for centuries, and how they’ve been represented visually on watches. If you’d like a more in-depth education on the topic, I recommend watching the recording of “The History of the Calendar,” a panel that F.P. Journe led at the Horological Society of New York in 2016.

As long as there have been calendars (at least since ancient Egypt) it seems there have been disagreements over how they should work, and suggestions for their reform. A number of books in our library at HSNY cover the history of calendars, including Michael Judge’s “The Dance of Time: the Origins of the Calendar,” David Ewing Duncan’s “The Calendar: The 5000-Year Struggle to Align the Clock and the Heavens – and What Happened to the Missing Ten Days,” “Mapping Time: The Calendar and its History” by E. G. Richards, and “Marking Time: the Epic Quest to Invent the Perfect Calendar,” by Duncan Steel. Incidentally, it seems to me that authors published a rash of these volumes around the turn of the millennium–I wonder why?

One spectacularly illustrated volume in our library is “The Phenomenon Book of Calendars,” originally published in the 1970s. On the back cover, the book boasts: “here, for the first time, all calendar systems past and present have been integrated in one graphically unique publication.” It even comes with a poster (image 1) that features many of these calendars for the years 1978-1979 including, but not limited to: Gregorian, Chinese, Hindu, Hebrew, Islamic, Aztec, Mayan, Roman, Bali, New Guinea, I Ching, and Zodiacal. In our calendar section, we also have books that cover some of these calendars in detail, including “Understanding the Jewish Calendar” and “Une Autre Temps,” which is a French language book about Balinese tika calendars. (A museum note explains how these carved wooden calendars help keep track of festivals and traditions in Bali.)

In James Atkinson’s “Epitome of the Whole Art of Navigation” (1782), a book in our library that I mentioned in my article about longitude, Atkinson covers the workings of the “Gregorian, or New Calendar” (see image 2, which shows the title page). The Gregorian calendar first replaced the earlier Julian calendar in 1582, so it was hardly “new” when this book came out, but Britain didn’t widely adopt the Gregorian system until the mid-18th century. Atkinson’s book went through many editions where information was added as it became useful.

As Atkinson explains, the chief difference between the two calendars was in the calculation of leap years. The Julian calendar includes a leap year every four years–but that was making the year a little too long on average, throwing off the dates of fixed events like the equinoxes. In the Gregorian reform, some of these leap years have been eliminated. Atkinson methodically instructs his readers on how to use the new calendar to calculate religious holidays, the moon age, and the exact time of high tides, which would have been particularly useful to sailors.

In 1793, French revolutionaries created a brand new calendar with decimal dates, as well as a decimal time system. Heavily symbolic, the calendar started a new era with year One in the year of the revolution (1789), though year One was later changed to the year of the founding of the French Republic (1792); the new system was called the French Republican calendar. French reformers devised the timekeeping system in an attempt to eliminate royal and religious influences and set the country on a more “rational” course. Each week had ten days, although there were still twelve months. Each day was also divided into ten hours with each hour lasting 100 minutes.

Ferdinand Berthoud, one of the most prominent and innovative European watchmakers of the 18th century, was a member of the committee that chose the winning proposal for decimal time. Below, a photo of a watch by Ferdinand’s nephew Pierre-Louis (Louis) shows how watchmakers in France adapted to the new scheme (image 3). There are ten hours in the center of the dial and a 100-minute track around the outer edge.

A number of watchmakers even tried to incorporate the new decimal system right alongside the 12-hour system in their designs, resulting in some ingenious, chaotic dial layouts. Image 4 shows an enameled watch dial from 1793-1795, which has both a 10-hour subdial and a 12-hour subdial, as well as a Republican calendar (left) and a Gregorian calendar (right). Both images are from the book “La Révolution Dans la Mesure du Temps,” edited by Catherine Cardinal. The French experiment lasted until around 1806–a turbulent period commemorated in our library by additional titles including “Time and the French Revolution” and “Cadrans de la Révolution.”

A well-known American calendar reform effort in the 20th century was the World Calendar, whose chief champion was Elisabeth Achelis. Achelis, a New Yorker who was heir to a rubber company fortune, became utterly (and somewhat inexplicably) obsessed with the idea of calendar reform after hearing a lecture on the subject in 1929. She adopted the cause as her passion and her life’s work.

You can read more about the World Calendar here, but the general idea is that there are four equal quarters of three months each. So far, so familiar. But this calendar regularizes the length of months (so each quarter has 91 days) and adds two additional off-calendar or intercalary days, Worldsday and Leapyear Day. By these alterations, the New Year begins every year on Sunday, the first of January, and each exact date occurs on the same day of the week, every year. You can see a schematic of the calendar in image 5, with the two intercalary holidays sticking out like page flags at the end of the months of June and December.

In “Of Time and the Calendar,” a 1955 volume in our library (image 6), Achelis claims the World Calendar she proposes would “lower taxes, reduce government costs, help home-budgeting, equalize salary payments” and other benefits. Among other things, paper calendars could be reused indefinitely because the year is the only number on the calendar that would need to be changed. Unfortunately the proposal caused problems for Jews and Christians alike because the intercalary days created two eight-day weeks, which would disturb the observance of the Sabbath.

In addition to writing several books on the subject of the World Calendar, Achelis started the Journal of Calendar Reform to promote the system, and we have a volume of the journal in our library (image 7). The journal’s cover shows another rendering of the world calendar flanked by the words “order,” “balance,” “stability,” and “harmony.” Although the proposal gained some traction with the League of Nations and later the United Nations, it was never widely adopted.

One of the great challenges of watchmaking has been to develop devices to track and display calendar dates that do not need to be frequently reset. Inventors of ingenious modern-day perpetual calendar watches have devised solutions for previously incalculable calendar quandaries. For instance, we have a book about the Vacheron Constantin 57260, which was one of the first watches to feature a Jewish calendar among its 57 (!!!) complications when it debuted in 2015. The Hebrew calendar uses a lunisolar model, meaning both the moon and the sun are taken into account when determining the length of months and years. Other recent complicated models have represented the lunisolar Chinese Traditional Complete calendar, including a 2023 Parmigiani Fleurier watch, and the lunar Hijri calendar that governs Islamic holidays.

Even among simpler timepieces, many watches and clocks feature moon phases, including the longcase clock at our library at HSNY. Image 8 shows the dial of our clock, with the moon waxing and waning contentedly across the top arc, in this photo nearly at full. If you want to build or repair a calendar watch or a clock with a moon phase mechanism, we have books for that, too! One is pictured in image 9.

Whether you’re excited about January 1, or whether it’s just another day to you, I hope you take a moment to think of the calendar as it flips forward, pulling us all along through our worst years and our best, our funerals, festivals, and our very human attempts to make sense of how time touches us.