<PackageReference Include="NETStandard.Library" Version="2.0.3" />

System.Globalization.Calendar

public abstract class Calendar : ICloneable
namespace System.Globalization { public abstract class Calendar : ICloneable { public const int CurrentEra = 0; public virtual CalendarAlgorithmType AlgorithmType { get; } protected virtual int DaysInYearBeforeMinSupportedYear { get; } public abstract int[] Eras { get; } public bool IsReadOnly { get; } public virtual DateTime MaxSupportedDateTime { get; } public virtual DateTime MinSupportedDateTime { get; } public virtual int TwoDigitYearMax { get; set; } protected Calendar(); public virtual DateTime AddDays(DateTime time, int days); public virtual DateTime AddHours(DateTime time, int hours); public virtual DateTime AddMilliseconds(DateTime time, double milliseconds); public virtual DateTime AddMinutes(DateTime time, int minutes); public abstract DateTime AddMonths(DateTime time, int months); public virtual DateTime AddSeconds(DateTime time, int seconds); public virtual DateTime AddWeeks(DateTime time, int weeks); public abstract DateTime AddYears(DateTime time, int years); public virtual object Clone(); public abstract int GetDayOfMonth(DateTime time); public abstract DayOfWeek GetDayOfWeek(DateTime time); public abstract int GetDayOfYear(DateTime time); public virtual int GetDaysInMonth(int year, int month); public abstract int GetDaysInMonth(int year, int month, int era); public virtual int GetDaysInYear(int year); public abstract int GetDaysInYear(int year, int era); public abstract int GetEra(DateTime time); public virtual int GetHour(DateTime time); public virtual int GetLeapMonth(int year); public virtual int GetLeapMonth(int year, int era); public virtual double GetMilliseconds(DateTime time); public virtual int GetMinute(DateTime time); public abstract int GetMonth(DateTime time); public virtual int GetMonthsInYear(int year); public abstract int GetMonthsInYear(int year, int era); public virtual int GetSecond(DateTime time); public virtual int GetWeekOfYear(DateTime time, CalendarWeekRule rule, DayOfWeek firstDayOfWeek); public abstract int GetYear(DateTime time); public virtual bool IsLeapDay(int year, int month, int day); public abstract bool IsLeapDay(int year, int month, int day, int era); public virtual bool IsLeapMonth(int year, int month); public abstract bool IsLeapMonth(int year, int month, int era); public virtual bool IsLeapYear(int year); public abstract bool IsLeapYear(int year, int era); public static Calendar ReadOnly(Calendar calendar); public virtual DateTime ToDateTime(int year, int month, int day, int hour, int minute, int second, int millisecond); public abstract DateTime ToDateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, int era); public virtual int ToFourDigitYear(int year); } }