We are excited to announce a new title in the Studies of the Weatherhead East Asian Institute book series: Making Time: Astronomical Time Measurement in Tokugawa Japan, published by the University of Chicago Press. The book’s author is Yulia Frumer, the Bo Jung and Soon Young Kim Assistant Professor of East Asian Science and Technology in the Department of History of Science and Technology at the Johns Hopkins University.
What is time made of? We might balk at such a question, and reply that time is not made of anything—it is an abstract and universal phenomenon. In Making Time, Yulia Frumer upends this assumption, using changes in the conceptualization of time in Japan to show that humans perceive time as constructed and concrete. In the mid-sixteenth century, when the first mechanical clocks arrived in Japan from Europe, the Japanese found them interesting but useless, because they failed to display time in units that changed their length with the seasons, as was customary in Japan at the time. In 1873, however, the Japanese government adopted the Western equal-hour system as well as Western clocks. Given that Japan carried out this reform during a period of rapid industrial development, it would be easy to assume that time consciousness is inherent to the equal-hour system and a modern lifestyle, but Making Time suggests that punctuality and time-consciousness are equally possible in a society regulated by a variable-hour system, arguing that this reform occurred because the equal-hour system better reflected a new conception of time — as abstract and universal—which had been developed in Japan by a narrow circle of astronomers, who began seeing time differently as a result of their measurement and calculation practices. Over the course of a few short decades this new way of conceptualizing time spread, gradually becoming the only recognized way of treating time.
We thank Professor Frumer for taking the time to discuss her book with us. Please read the following Q&A to learn more about the research and questions that drove her project.
Could you tell us how you became interested in the topic of timekeeping in Japan?
It was when I first learned that people in Tokugawa Japan measured time in variable, unequal hours. This system seemed so alien and counterintuitive that I could not help but wonder how people lived their lives in a world where hours kept changing their length. When I started reading more about this system of timekeeping, I discovered that a similar system was, in fact, used in Europe, but it was gradually abandoned around the 14th century in favor of our current system of equal hours. Many of the scholars writing about Europe claimed that the variable hours system was abandoned because it was not suited for an urban lifestyle, or that it couldn’t have been used for calculating time-based wages, or that it was impossible to measure with the then-favorite new European technology: mechanical clocks. But here is the thing: the city of Edo in 1700 had a population of close to a million—several times more than any European city—and they did not have any problem using variable hours. Work contracts simply adjusted for the seasonal length of hours (Japan was never lacking paperwork). And then there were the clocks: beautiful (and very steampunky) brass devices, many of which did not even resemble European clocks. Japanese artisans seemed to have done something others claimed was impossible, and adjusted the clockwork mechanism to measure hours of variable length. So even in my very initial stages of research, I saw that the Japanese case offered a unique opportunity for exploring questions regarding perceptions of time and time measuring practices.
How was Japan’s pre-1873 way of measuring time different from that of other countries and why do you believe it was different?
Before the Meiji calendrical reform, the day in Japan was divided into twelve hours—six hours for daytime and six hours for nighttime. Since the length of daytime and nighttime changes throughout the seasons, relative length of hours changed too. So, in the winter one would have really long nighttime hours (lasting something like two–and-a-half hours in our terms) and short daytime hours, but in the summer it was the opposite and daytime hours were longer than nighttime ones. People in Tokugawa Japan did not adjust the length of hours every day, but once every 14-15 days that marked a “mini-season” — 1/24th of a solar year. What determined the precise length of hours were the moments designated as the beginning and the end of the day.
It may sound all very “natural” and “free-range,” but this system was far from that. It was not about the sunrise, since it becomes bright enough to start the day before the sun appears above the horizon. So in order to have a functioning society, people had to decide what point in the long process we call “dawn” would mark the beginning of the day. This decision was delegated to astronomers, who came up with a mathematical algorithm that made it possible to create a calendar. Every household had at least one of those, and adjusted their clocks accordingly. Bell keepers too had detailed timetables that allowed them to ring the bells in the appropriate hour corresponding to the astronomical calculations during each “mini-seasons.” In a sense, this system required not less but actually more regulation and government supervision than our current one.
What do you think led to the change from the variable-hour system to an equal-hour system of timekeeping in 1873?
What changed by the mid-nineteenth century was the way people thought about the measurement of time. Previously, there were different coexisting timekeeping systems in Tokugawa society—variable hours, Buddhist, marketplace, several astronomical systems, etc.—that did not have a clear hierarchy between them. The assessment of whether one system was good or bad depended on how appropriate that particular timekeeping system was for the chosen task. Astronomers too did not think that their system was somehow better than others, and when they went home they happily used whatever timekeeping conventions they found useful. However, in their work, once astronomers started thinking about celestial cycles in geometrical terms, they decided that Western timekeeping system, which represented mean solar time, was the most suitable for their goals. In the beginning of the nineteenth century astronomy (and the related sciences of geography and navigation) gradually emerged as a cultural model of rationality and progress, and by mid-nineteenth century intellectuals began treating astronomical time as the Time. Their desire to institute astronomical time as the standard in Japan was only bolstered by their understanding that astronomical time was Western time.

Why do you believe that punctuality and time-consciousness could have been equally possible in a society regulated by a variable-hour system?
First of all, when we look at the sources—even earlier in the Tokugawa period, but certainly in the nineteenth century—we realize that people were highly time-conscious. Europeans who visited Japan noted that Japanese people seemed to constantly note time. If you look at people’s diaries, you see that every daily activity they mentioned is accompanied by an hour stamp. Court documents, contracts, and everything else revolved around time.
Speaking on a more abstract level, though, I should note that “punctuality” is a relative term. The precise range of time that is considered to be within the frame of being “punctual” is a societal decision. I recently took an Amtrak train, and when I looked at the app trying to estimate my arrival, it informed me that the status was “on time” and also that the train arrived five minutes after the scheduled time.
Now, what is needed for functioning in the modern society is the ability to synchronize our devices. The precise system of dividing the day doesn’t really matter long as everybody agrees. Think of it: what we call “noon” today rarely coincides with the astronomical solar noon (when the sun is at its zenith). Not only do most of us not live precisely in the right place on the time zone, but also only four days a year do solar days last exactly 24 hours. Most of the people do not really care about these inconsistencies because they do not really matter for our functioning. As long as we all agree to call a certain point in time “noon,” there would be no confusion. In the same way, if everybody agrees that during a certain season two o’clock means one thing but in another season it is something else, then there is no problem. In the same way that we handle transitions to daylight savings, people then handled the change of hours in the Tokugawa period (and could have handled in the later period too).
What kinds of sources and archives did you consult in the course of your research?
For my analysis of astronomers’ work I relied on their manuscripts, notes, and letters. Like many other scholars, I made an extensive use of the National Diet Library in Tokyo. However, a real treat was the opportunity to go to smaller, local archives. I was lucky to visit the Tohoku University Archive that hosts the Wasan Collection before 3.11. Many interesting finds came from the Hazama Bunko in Osaka. And then there was the Koju Bunko in Toyama; to get there, I had to take a train from Kanazawa, then change to another train, and then take a bus that ran only twice a day. But it was all worth it. The archivists there were extremely kind and helpful.
In addition to written materials, I treated Japanese clocks themselves as historical sources. One of the most wonderful places I visited was the Seiko Museum. People often rave about the tiny Daimyo Clock Museum, which is nice, but, in terms of variety, the Seiko Museum has so much more to offer. The only thing is that it is a bit off the beaten path, and not many people are willing to schlep to that part of Tokyo. They have a fantastic collection, and all the people who work there are extremely helpful and friendly.
How would you like Making Time to expand or challenge our understandings of how time is constructed and understood?
We tend to take for granted the existence of an abstract, independent of human activities entity called ‘Time.’ Thinking about time as abstract, we assume that the only criterion that matters for measuring time is precision—the more precise the better. Making Time shows that the very notion of abstract, independent time is only one of the ways of thinking about time, and it is something that emerged in the modern period. This modern understanding of time conceals the fact that we neither understand time as abstract nor use it in a uniform matter. In reality, our understanding of time is informed by associations with very concrete practices, images, and artifacts, and those associations change according to situations in which we need to measure time. In fact, the notion of abstract time itself is rooted in very concrete astronomical imagery and in calculations that treated time as a proxy for celestial motion. If there is one thing I want the readers to take away from Making Time, it is that our understanding of abstract concepts, such as time, is based on our lived experiences.
What research findings surprised you the most when working on this project?
The most shocking experience for me was to read testimonies about Takahashi Kageyasu’s trial. Kageyasu was the Bakufu astronomer who gave Philip Franz von Siebold copies of Inō Tadataka’s precise maps of Japan (in exchange for maps of the world and scientific instruments). When the maps were discovered in Siebold’s possession, Kageyasu was imprisoned and he died shortly after “of a sudden and grave disease.” But because the trial was not finished, they decided to preserve Kageyasu’s body, so that the court could deliver him his sentence. So there were these testimonies describing how Kageyasu’s body was emptied of entrails, stuffed with salt, and put into a barrel with a hole in the bottom (to let the rotting juices out). By the end of this process, Kageyasu’s body apparently looked like a dried fish. Reading about this process was quite horrifying, and I am sure that people who wrote it down were horrified as well. I never expected that research on clocks and time would lead me to so much human drama.
Could you tell us about your next book project on robotics in Japan?
It is not a secret that humanoid robots are big in Japan—people adore them, numerous labs are working on them, and the technologies those labs develop are, in and of themselves, quite idiosyncratic. For many Americans, Japanese robots look scary, but people in Japan often say that “robots are friends.” When asked “what makes humans human,” many Americans would answer “intelligence,” but in Japan the answer would often be “expressiveness.” The obvious question is ‘why?’ In my upcoming book, I focus on a series of humans who made humanoid robots in Japan. I look at the factors that shaped their ideas about humanity—for example, their disciplinary affiliations, the scientific theories that guided them, the media that surrounded then, and the cultural tropes about building machines that they learned. Insights into these factors helped me understand how these humans would have answered the question “what makes machines look human-like,” and how these hypothetical answers shaped the kind of technological problems roboticists encountered, and the solutions they came up with.
What led you from researching clocks to researching robotics?
It may sound like a drastic departure from my work in Making Time, but it is not. First of all, clock-making and automata-making were technologically intertwined in the nineteenth century, when my book starts. But even more importantly, the question I ask in this project is very similar to the one that stands at the core of my research in to time-measurement. Previously, I looked at the relationship between the shaping of the concept of time and the time-keeping technologies. Now, I ask the about the relationship between people’s perception of humanity and the development of the field of Japanese robotics. In both projects I point out a very concrete and historically contingent basis for our understanding of abstract concepts—something that we assume we all know, but then discover that we do not necessarily agree on the details.
