TOKYO (AFP) - The abdication of Japan's Emperor Akihito on April 30 will quite literally mark the end of an era, the Heisei era of his rule, and highly secretive talks have been going on for months on what to call the next one.
This is anything but a procedural issue, as the name of the era has a tangible effect on the daily lives of the Japanese as well as a psychological impact on the nation.
Japan is the only country in the world still using Chinese-style imperial calendars. It might be 2019 in much of the world, but in Japan it is Heisei 31, or the 31st year of Akihito's reign.
While the Gregorian calendar is also widely used in Japan, imperial dates feature on government documents, newspapers, and commercial calendars.
"It is easier to imagine what the time was like if you have eras," said Mr Kunio Kowaguchi, president of major calendar maker Todan.
"For instance, we remember it was early Heisei that the bubble burst," he told AFP, referring to the collapse of Japan's speculation-driven economy.
The upcoming end of the Heisei period was even reportedly a factor in the government's decision to implement death sentences last year against 13 members of the Aum cult behind a 1995 sarin attack.
Government officials apparently wanted to a draw a line under the cult's attacks before the Heisei era ends. All 13 executions were carried out in July.
Japan has had nearly 250 eras since adopting the system in the 7th century.
In the past, emperors would switch era names mid-reign to mark a fresh start after natural disasters or crises.
But more recently, an era has run the entire length of a monarch's rule.
Crown Prince Naruhito ascends the Chrysanthemum Throne on May 1. His era name will be announced at 11.30am next Monday (April 1) - a month ahead of the ceremony.
And speculation over what the name might be has been rife.
There have been more than 10,000 entries in a public guessing competition run by a liquor company, hoping to win a vintage bottle of sake from year one of the Heisei era (1989).
A new 'Y2K'?
A new era is a real challenge for companies like Kowaguchi's, which produces 10 million calendars a year, many featuring both Western and imperial dates.
Printing begins a year before release, so it was too late for his 2019 run to feature the new name.
The new imperial era will be the first since the IT revolution, and the tech sector is girding for the transition.
It has inspired comparisons to the "Y2K" bug ahead of the year 2000, when experts worried about a tech apocalypse, fearing that computers would not understand the new date.
"What is largely different from the time of the Y2K problem or the switch to the Heisei period is that IT is widely used and information is passed around among Internet-capable devices," said Mr Kazunori Ishii, spokesman for Microsoft's Japan arm.
"We can't predict exactly what will happen," he said, though he noted that major disruption was "unlikely".
Software used in Japan that converts between Western and imperial dates will need to be updated with the new era, and code and fonts for the new name will also need to be created.
The 85-year-old emperor's decision to abdicate gave experts a rare head start in choosing the new era's name.
The task falls to the government rather than the palace and, like many matters involving the royal household, is shrouded in secrecy.
There are stringent guidelines requiring the name to have two characters, be easy to read and write, and not use common names.
'New era, new mindset'
The new name is also unlikely to start with the first letter of any of the last four eras: Heisei, Showa, Taisho and Meiji.
And because each era name is considered "sacred", any name put forward but rejected in the past cannot be proposed again.
One of the few people familiar with the challenge is Mr Junzo Matoba, a former bureaucrat who helped look for new names during the last years of Emperor Hirohito's Showa era, in the late 1980s.
"Some people thought it was irreverent to think about the next era" while the emperor was still alive, he told AFP.
"I had to work secretly."
He consulted academics on Asian history and literature while trying to maintain a low profile.
"I found myself caught up in such a difficult task - I was sitting under the Sword of Damocles," the 83-year-old told AFP last year.
Japan's government is believed to have a shortlist of names, but has been mum on potential choices.
The government does not even disclose the names of scholars asked to put up candidate names.
A nine-member panel is to make a pick out of the candidates. Parliament leaders' opinions will be heard on it and then Cabinet ministers will meet to give the final go-ahead.
"Japanese people love to 'reset' things," said Mr Matoba.
"A new era, a new mindset."