[maxnoe]

Not a Problem in this case, the era is always a single character, a newly formed ligature of two kanjis.

The code point was already reserved in unicode 11.0, so you could even just the unicode code point.

[kevin_thibedeau]

The real world is not so perfect. I never see Heisei or Showa, or earlier reigns as a single character. The Japanese are also not fully onboard with Unicode so there's an extra level of effort needed if you want to get into a normalized form.

[thaumasiotes]

For this specific question, I strongly suspect that whatever the length of your Heisei string is, it's safe to assume that the new era string will be the same length.

[massivecali]

>The real world is not so perfect. Perfect summation. Curious how this will also impact other consumers of Japanese data.

[dialogbox]

Then it looks even harder. How do we handle it if our system doesn't support Unicode 11.0? Is platform upgrade only option?