This class implements the standard Western calendar, and also the default culture-invariant calendar. It defines two eras (B.C./B.C.E. and A.D./C.E.), 12 months per year. A leap year occurs every 4 years except for years divisible by 100. However, years divisible by 400 are leap years. Only the current era (A.D./C.E.) is recognized by .NET's implementation of the Gregorian calendar.

public class GregorianCalendar : Calendar {
// Public Constructors
   public GregorianCalendar( );
   public GregorianCalendar(GregorianCalendarTypes type);
// Public Static Fields
   public const int ADEra;
// =1
// Public Instance Properties
   public virtual GregorianCalendarTypes CalendarType{set; get; }
   public override int[ ] Eras{get; }     
// overrides Calendar
   public override int TwoDigitYearMax{set; get; }    
// overrides Calendar
// Public Instance Methods
   public override DateTime AddMonths(DateTime time, int months);                  
// overrides Calendar
   public override DateTime AddWeeks(DateTime time, int weeks)
// overrides Calendar
   public override DateTime AddYears(DateTime time, int years)
// overrides Calendar
   public override int GetDayOfMonth(DateTime time); 
// overrides Calendar
   public override DayOfWeek GetDayOfWeek(DateTime time);  
// overrides Calendar
   public override int GetDayOfYear(DateTime time);  
// overrides Calendar
   public override int GetDaysInMonth(int year, int month, int era)
// overrides Calendar
   public override int GetDaysInYear(int year, int era);        
// overrides Calendar
   public override int GetEra(DateTime time);        
// overrides Calendar
   public override int GetMonth(DateTime time);      
// overrides Calendar
   public override int GetMonthsInYear(int year, int era);
// overrides Calendar
   public override int GetYear(DateTime time);       
// overrides Calendar
   public override bool IsLeapDay(int year, int month, int day, int era)
// overrides Calendar
   public override bool IsLeapMonth(int year, int month, int era)
// overrides Calendar
   public override bool IsLeapYear(int year, int era);       
// overrides Calendar
   public override DateTime ToDateTime(int year, int month, int day,
       int hour, int minute, int second, int millisecond, int era)
// overrides Calendar
   public override int ToFourDigitYear(int year);    
// overrides Calendar
}

Hierarchy

System.Object Calendar GregorianCalendar