Yes, they have two date systems in common use. It's only the year that changes though. And there's no way to confuse the two, usually. If you write "2023" instead of "令5" it's pretty obvious. I suppose there is a potential for confusion if one just writes a two-digit year though.
Wat? Like their alphabet, do the Japanese have some double system?
China does this normally. Either YYYY.MM.DD OR YYYY年MM月DD日
Yes, they have two date systems in common use. It's only the year that changes though. And there's no way to confuse the two, usually. If you write "2023" instead of "令5" it's pretty obvious. I suppose there is a potential for confusion if one just writes a two-digit year though.