Then there is Japanese that have to worry if their system still working tomorrow because of Showa 100 Year Problem

Short summary: Basically similar to Y2K, when changing era in Japan last last time from Showa to Heisei, in order to save space, programmer at the time continue to use Showa as base so Heisei 2 actually recorded in computer as Showa 65. Tomorrow, which is 2025, is Showa 100. And you get the idea.