The Emperor’s Calendar

The Emperor’s Calendar

In Japan, an year is more than just a number. But is this culturally rich system still relevant today?

30st April 2019 is going to be a momentous day for the people of Japan. For the first time in over two centuries, the Emperor of the Chrysanthemum Throne is going to voluntarily resign his position.

Emperor Akihito has been reigning for thirty years so far. He ascended the throne in 1989, right at the start of the Heisi Era. We are now in Heisi 31, and the thirty-first year of the Emperor’s rule.

But now, as old age catches up, and he has an ongoing battle with cancer, the Emperor has decided to step aside and make way for his successor.

The announcement was a momentous one. A special law had to be passed in Parliament, allowing the Emperor to resign: usually, it’s death that does the job. That was, however, only the tip of the iceberg.The change of emperor would trigger a more fundamental change that would affect government offices, stamp printing, newspapers, postal services, banks, private companies, and pretty much anything that involves a computer.


That the Emperor ascended the throne at the start of an era is no coincidence. Japan follows the traditional gengō system, which means the calendar year gets reset every time a new ruler comes in.

Different calendar systems have different ways of counting the years. Some, like the now-widespread Gregorian calendar, count upwards from a fixed date like the birth-year of Jesus Christ — or four years after, as the case may be.

Others operate on a cyclic system, like the Tamil calendar which goes round every sixty years: the year starting mid-April is Vikari; the Gregorian year 1959 was Vikari, and the year 2079 will also be Vikari. Incidentally, so is the name of my cat.

In Japan, the year count is more intertwined with history. There’s no fixed pattern that can be predicted in advance. Instead, era or gengō changes are chosen to mark crucial milestones in the life of the nation: a change of emperor, an upheaval at home, or a period of recovery after natural disaster.


People often refer to periods of time casually as “the time of the earthquake” or “the year that rebellion happened”. In Japan, that’s actually formalised, as “Tenpō” and “Keiō”.

But changing eras can also be confusing. There have been nearly 250 gengō till date, and it’s not possible to remember all of them. To simplify things, the “one emperor, one era” system was adopted in 1889.

Still, those eras are associated with more than just emperors.

People associate the Meiji era, between 1898 and 1912, with a period of Western-inspired industrialisation, for instance. And the following Showā era reminds one of the Second World War, and the recovery and economic development that came after.


For Russia and the USA, the Showā era would be associated with the World War too, but also with the Cold War that followed. The nations weren’t exactly at war, but were competing to get the most advanced armies, infrastructure, and technology in general.

The Showā gengō also saw what was possibly the world’s first cyberattack.

It started with Russia’s new pipeline, transporting oil from Siberia to Moscow. At that time, such pipelines were starting to be software-controlled, but Russia didn’t have the expertise to make such software. So, they decided to copy the files from Canada.

When the USA heard of this, they sent their Central Investigation Agency, or CIA, to intercept the software. They implanted a code that would usually do nothing, but then, at a specific moment, would be triggered into action.

The resulting gas explosion was so huge, its flames could even be seen from space.


The USA denies hacking the system: their version is, a worker tried to keep gas flowing by increasing the pressure, instead of fixing a leak that had been found.

Assuming the other story’s true, however, the CIA code is an example of a ‘logic bomb’. That’s a piece of destructive code that can’t really be detected, because it does nothing. But it’s actually waiting for its trigger — a specific time, or a certain sequence of events — to spring into action and wreak havoc.

Logic bombs could be made by disgruntled employees, leaving a company-record-deleter for the moment they get removed from payrolls. The could be implanted by countries or individuals to attack one another. Or, they could crop up by accident.

For example, there’s the logic-bomb of sorts that was triggered by the Gregorian year “2000”.


The first inkling that something was wrong came when Marks & Spencer, the well-known department store, rejected a perfectly good shipment of canned meat.

Marks & Spencer had an efficient, computerised system. All incoming products would have their expiry dates calculated, and they’d be rejected if they turned out too old. But the computers at Marks & Spencer, like most others of the time, had a certain format for storing dates. They would only save the last two digits of the year, like 26 for 1926 — an efficient system, since computers for mass consumption came out only around the ’60s, after all.

But this was the year 1996, and the meat expired in 4 years. When the computer tried calculating by shifting the digits forward, 99could only be followed by 00 .

The computer thought the canned meat expired in 1900 — which would make it ninety-six years past its expiry date.


Marks & Spencer’s finding was one of many events that triggered what is now known as the ‘Y2K’ scare. Because most computers worked in the same way, they would all be affected by the year-change problem.

Word was going round that, when the year 2000 dawned, computer-powered systems would collapse all around the world (including Siberia).

Of course, that didn’t happen — but only because programmers worked hard to fix the problem, making their computers recognise four digits of the year rather than two.

A similar problem is facing Linux and other Unix-based systems — that means web-servers, supercomputers, laptops, embedded devices, and your Android or Apple smartphone. These systems count time as the number of seconds that have elapsed since 00:00:00 Thursday, 1 January 1970 UTC, but only upto a certain number of digits. Unless software updates are made, on 03:14:07 Tuesday, 19 January 2038 UTC, all the timings will reset to zero.

And now, the Emperor’s resignation is giving Japan it’s own “Y2K moment”. Computer systems need to deal with a change of era. And, because most computers have been in the Japanese mainstream only during this Heisi era, they’ve never experienced such a situation before.

Luckily, many computers already have an option to configure gengō. Programmers either had the foresight to add it in, or quickly coded it following the Emperor’s announcement.

Microsoft has a special website dedicated to era-change software updates. And, even if some of the software doesn’t rely on calendars, they see it as an opportunity to make people update their software anyway.


The calendar change is, of course, going to affect more than just computer.s Government records, news announcements, future dates — everything has to be updated for the new era. Calendar business is set to boom.

And, some people are questioning whether to continue with this old system at all.

For all its elegance, the gengō system can be quite confusing. What date was it 40 years ago? To answer that question, you have to know the length of this era, and that of the previous one, and calculate backwards. The further you go, the worse it gets.

It’s a bit like calculating dates across months, I guess, but more complicated.

A lot of the younger generation in Japan use the Gregorian calendar because it’s more convenient. Starting now, the Foreign Office is going to switch too, to avoid confusing other countries further.

Already, a lot of compromises have had to be made. It’s not acceptable to decide the next era’s name before it starts, because it’d be like anticipating the Emperor’s death. But this time, the government decided to release it a month in advance, to give people time to prepare. A special top-secret committee was formed to choose the name, and everyone involved had to surrender their cellphones to avoid a leak.

In any case, Japan uses the Gregorian calendar for months and days. Why not use it for years as well?


While many are all for “modernising” the calendar, others aren’t so sure. The gengō is an age-old tradition; an integral part of Japanese culture. If it goes then what next? Will the do away with the monarchy itself?

The gengō system gives people a sense of fixedness; it provides waypoints to stop and reflect on the future of the nation.

And, all said and done, the gengō count is not such a big confusion. Months and days still follow the internationally recognised system. As for era change, now that it’s been implemented in software and industries, will be relatively easy to update next time.

No matter what system they use, people don’t see years as just numbers. Each year has its context and associations: it’s related personal, national, and global events. Whether it’s the year you were born or the year Germany reunited, every year marks a numbered chapter in the story of the nation.

But it’s only in Japan, with the gengō system, that these chapters can have titles.


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