Setting/Testing the New Japanese Riewa Era in NLS
[Update: https://support.microsoft.com/en-us/help/4469068/summary-of-new-japanese-era-updates-kb4469068 lists the updates available for Windows to enable Reiwa support]
I talked about the upcoming new Japanese Era, and today the new era name was announced! Since the era data is available in the registry on Windows, people can add the Reiwa Era information to the registry immediately. Though Reiwa doesn't start until May 1, administrators may want to test their software with the new Reiwa era.
You can add an entry for 2019 05 01 to the registry, such as this:
Windows Registry Editor Version 5.0 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls\Calendars\Japanese\Eras] "1868 01 01"="明治_明_Meiji_M" "1912 07 30"="大正_大_Taisho_T" "1926 12 25"="昭和_昭_Showa_S" "1989 01 08"="平成_平_Heisei_H" "2019 05 01"="令和_令_Reiwa_R"
Note that though much of NLS recognizes the era, it doesn't actually begin until May 1st. Additionally, some software on Windows does not depend on NLS, so the registry entry may not enable Reiwa for all applications.
Since the era doesn't actually start until May 1st, some parts of the system won't show the 令和 era until May 1st. Other parts of the system may use the new era as soon as it's exposed in the registry. If you want to test the complete behavior after May 1st to ensure that your system behaves as expected in Reiwa, you may want to temporarily adjust your system clock to a date after May 1st for testing.
Depending on your preference for Gannen or Ichinen, you may also want to see this post: https://blogs.msdn.microsoft.com/shawnste/2018/11/12/gannen-vs-ichinen/