TOKYO — Lost data. Emails that disappear into the ether. Servers that never connect.

All thanks to the ascension of a new emperor to the Chrysanthemum Throne.

Japan is scrambling to update software, revise forms and print new calendars before May 1, when the world’s third-largest economy begins a new imperial era. For most of the rest of the world, it will remain the year 2019 when the clock strikes midnight. Across Japan, which relies internally on an ancient calendar that honors a reigning emperor, it will be the first day of the first year of the age of Reiwa.

The new era, christened just weeks ago , will force the country’s sprawling bureaucracy to literally turn back the clock to Year 1. Experts compare it to Y2K, the digital threat in the lead-up to the year 2000, if on a much smaller and less consequential scale.

“The change of the era name will have a huge effect on big companies that have complicated systems,” said Gaku Moriya, deputy director of the information technology innovation division at Japan’s Ministry of Economy, Trade and Industry, or METI.