Algorithms are tricky things to write. The problem for coders is that many programs could be unable to the parse the transition. For example, a software program might be pulling a date from the 40th year of the Heisei era which, unlike a traditional calendar, simply won’t exist. Some other programs won’t know what to do about having two partial eras occurring in the same calendar year.
Unicode — the international standards organization — faces an even tighter timeline. The next Unicode iteration, version 12, is destined to arrive in March 2019, and the new character for the Japanese era may be ready — or it might not. To offer a nimble solution, the Unicode group is considering launching a second update — 12.1 — as soon as they can ensure its stability, and then pressure software developers to implement it immediately.
So all eyes will be on Japan next April. Ever the pragmatists, some Japanese banks and tax organizations are deciding to coast with their current software packages, and pretend, for business purposes only, that the emperor holding the Chrysanthemum Throne will remain unchanged in 2019.