Japan has a system of era names, and this system is used in parallel with the western system of dates. This year, for example, is Heisei 30. This system goes back to 701, when the Taihō era began. (There are a few possible earlier eras, but there were substantial intervals between them, and some historians suspect that they were later constructions.) Historically, a typical era was about five years long, and eras were almost never changed at the beginning of the year. Thus, for example, the change between the Manji and Kanbun eras happened on the 25th day of the 4th month, which was 23 May 1661. However, until the nineteenth century the change was retrospective, so that someone writing a diary entry in the third month of Manji 4 would refer to the year as Manji 4, whereas someone writing about the same event two months later would refer to the year as Kanbun 1. These days, the change is not retrospective. The first day of Heisei 1 was 8 January (1989), but the 7 January was Shōwa 64, and is still referred to as such now. (Eras count from 1, not 0.)
This system was an imitation of the Chinese calendar, but it was independent of the Chinese eras. Most Asian countries used the Chinese eras, and Japan’s refusal to do so was an assertion of independence, and an occasional source of conflict with the Chinese. Eras were changed in response to significant events, such as major earthquakes, or the discovery of resources, or the appearance of remarkable phenomena or animals. An early era, Keiun (704–708), has a name meaning “Auspicious Cloud”, and was inaugurated because an auspicious cloud was seen. On the other hand, the Meiwa era (1764–1772) was concluded, at least in popular myth, because the ninth year of the era was marked by many disasters, and, in Japanese, was pronounced as “Meiwakunen”, which also means “Troublesome Year”.
The era names are taken from Chinese classics, and are supposed to have good meanings, relatively easy characters (so that people can write them), and pronunciations that do not sound inauspicious, as well as not being the same as era names that have previously been used in Japan or any other Asian country. Meeting all of these conditions is difficult, as the Meiwa era demonstrates.
Eras have always been formally established by the Tennō, so that in the period in the fourteenth century when there were two Tennō, from different lineages, at the same time, there were also two era names at the same time. People used the era name established by the Tennō of the lineage they supported. Since the Meiji era (from 1868), the era name has been changed once in the reign of each Tennō, near the beginning of his reign. This is why the Shōwa era was 64 years long; Shōwa Tennō reigned for a long time. (It has always been the custom for a Tennō to be granted a new name on death, and since Meiji this name has been the name of his regnal era. Referring to the current Tennō by the name of the current era is extremely impolite, and very inauspicious, and I don’t recall ever seeing it happen in Japan. Conversely, referring to a dead Tennō by any other name is also just not done; the official English form for the name of the previous Tennō is Emperor Showa.)
As you can imagine, era names are a bit confusing. If you read a historical account saying that something happened in Genroku 6, you probably do not immediately know when, unless that’s an era you happen to know. With over 1300 years of history and a typical period of five years or so, there are literally hundreds of era names to remember. In the modern period, you need to remember the day on which the era changed.
Next year, the current Crown Prince will become Tennō on May 1st, and the general assumption is that a new era will start on that day. This has got the Shinto authorities rather exercised.
First, they strongly encourage the use of era names rather than western style dates, in part because it is Japanese tradition, and in part because of the close connection to the Tennō. For example, the government has recently proposed to give the expiry date of driving licenses in western style, and the Shinto authorities are opposed. This is something of a rearguard action, but they are committed to fighting it.
The change raises a problem in this context. There is a lot of talk about announcing the new era name in advance, so that people can make the necessary preparations: printing documents with the new era name on, for example, or preparing forms with an option to choose the new era. Several organisations are talking about using this opportunity to switch to western dates, and if they do not get advance notice of the new era, they are even more likely to do so. Thus, from that perspective the Shinto authorities are strongly in favour of advance notice.
However, this is the era name for the new Tennō’s reign. That means that it should, formally, be promulgated by the new Tennō. However, he cannot do that until he actually is Tennō. This creates a serious conflict, which has led to some debate in the pages of Jinja Shinpō.
The solution that has been proposed in the Shinto community is announcing the new era name on May 1st, but having it come into effect later, possibly as late as January 1st 2020. There are precedents; Meiji Tennō became Tennō more than a year before the era name was changed, for example. Having the era change at the beginning of the year would also make it easier to use, and further discourage people from moving to western style. As a nice side benefit, the Tokyo Olympics and Paralympics would happen in New Era 1, which is as easy to remember as 2020.
The decision is, of course, made by the government, and they have not yet said anything formal. The current expectation is that the announcement will be made in late March, and the era will change on May 1st, but the current Prime Minister is quite close to the Shinto world, and on something like this may well listen to them.
This essay may raise a question in readers’ minds. What does this have to do with Shinto? It is a good question, and the only answer I can offer is that the Shinto community is very concerned about it, in their capacity as Shinto priests.