https://learn.microsoft.com/ja-jp/dotnet/api/system.globalization.eastasianlunisolarcalendar.twodigityearmax?view=netframework-4.8
EastAsianLunisolarCalendar.TwoDigitYearMax Property (System.Globalization) | Microsoft Learn
Gets or sets the last year of a 100-year range that can be represented by a 2-digit year.
property systemglobalizationmicrosoftlearn