JulianCalendar.IsLeapDay(Int32, Int32, Int32, Int32) Method

Definition

Determines whether the specified date in the specified era is a leap day.

public:
 override bool IsLeapDay(int year, int month, int day, int era);
public override bool IsLeapDay (int year, int month, int day, int era);
override this.IsLeapDay : int * int * int * int -> bool
Public Overrides Function IsLeapDay (year As Integer, month As Integer, day As Integer, era As Integer) As Boolean

Parameters

year
Int32

An integer that represents the year.

month
Int32

An integer from 1 to 12 that represents the month.

day
Int32

An integer from 1 to 31 that represents the day.

era
Int32

An integer that represents the era.

Returns

true if the specified day is a leap day; otherwise, false.

Exceptions

year is outside the range supported by the calendar.

-or-

month is outside the range supported by the calendar.

-or-

day is outside the range supported by the calendar.

-or-

era is outside the range supported by the calendar.

Examples

The following example calls IsLeapDay for the last day of the second month (February) for five years in each of the eras.

using namespace System;
using namespace System::Globalization;
int main()
{
   
   // Creates and initializes a JulianCalendar.
   JulianCalendar^ myCal = gcnew JulianCalendar;
   
   // Creates a holder for the last day of the second month (February).
   int iLastDay;
   
   // Displays the header.
   Console::Write( "YEAR\t" );
   for ( int y = 2001; y <= 2005; y++ )
      Console::Write( "\t {0}", y );
   Console::WriteLine();
   
   // Checks five years in the current era.
   Console::Write( "CurrentEra:" );
   for ( int y = 2001; y <= 2005; y++ )
   {
      iLastDay = myCal->GetDaysInMonth( y, 2, JulianCalendar::CurrentEra );
      Console::Write( "\t {0}", myCal->IsLeapDay( y, 2, iLastDay, JulianCalendar::CurrentEra ) );

   }
   Console::WriteLine();
   
   // Checks five years in each of the eras.
   for ( int i = 0; i < myCal->Eras->Length; i++ )
   {
      Console::Write( "Era {0}:\t", myCal->Eras[ i ] );
      for ( int y = 2001; y <= 2005; y++ )
      {
         iLastDay = myCal->GetDaysInMonth( y, 2, myCal->Eras[ i ] );
         Console::Write( "\t {0}", myCal->IsLeapDay( y, 2, iLastDay, myCal->Eras[ i ] ) );

      }
      Console::WriteLine();

   }
}

/*
This code produces the following output.

YEAR            2001    2002    2003    2004    2005
CurrentEra:     False   False   False   True    False
Era 1:          False   False   False   True    False

*/
using System;
using System.Globalization;

public class SamplesJulianCalendar  {

   public static void Main()  {

      // Creates and initializes a JulianCalendar.
      JulianCalendar myCal = new JulianCalendar();

      // Creates a holder for the last day of the second month (February).
      int iLastDay;

      // Displays the header.
      Console.Write( "YEAR\t" );
      for ( int y = 2001; y <= 2005; y++ )
         Console.Write( "\t{0}", y );
      Console.WriteLine();

      // Checks five years in the current era.
      Console.Write( "CurrentEra:" );
      for ( int y = 2001; y <= 2005; y++ )  {
         iLastDay = myCal.GetDaysInMonth( y, 2, JulianCalendar.CurrentEra );
         Console.Write( "\t{0}", myCal.IsLeapDay( y, 2, iLastDay, JulianCalendar.CurrentEra ) );
      }
      Console.WriteLine();

      // Checks five years in each of the eras.
      for ( int i = 0; i < myCal.Eras.Length; i++ )  {
         Console.Write( "Era {0}:\t", myCal.Eras[i] );
         for ( int y = 2001; y <= 2005; y++ )  {
            iLastDay = myCal.GetDaysInMonth( y, 2, myCal.Eras[i] );
            Console.Write( "\t{0}", myCal.IsLeapDay( y, 2, iLastDay, myCal.Eras[i] ) );
         }
         Console.WriteLine();
      }
   }
}

/*
This code produces the following output.

YEAR            2001    2002    2003    2004    2005
CurrentEra:     False   False   False   True    False
Era 1:          False   False   False   True    False

*/
Imports System.Globalization

Public Class SamplesJulianCalendar   
   
   Public Shared Sub Main()

      ' Creates and initializes a JulianCalendar.
      Dim myCal As New JulianCalendar()

      ' Creates a holder for the last day of the second month (February).
      Dim iLastDay As Integer

      ' Displays the header.
      Console.Write("YEAR" + ControlChars.Tab)
      Dim y As Integer
      For y = 2001 To 2005
         Console.Write(ControlChars.Tab + "{0}", y)
      Next y
      Console.WriteLine()

      ' Checks five years in the current era.
      Console.Write("CurrentEra:")
      For y = 2001 To 2005
         iLastDay = myCal.GetDaysInMonth(y, 2, JulianCalendar.CurrentEra)
         Console.Write(ControlChars.Tab + "{0}", myCal.IsLeapDay(y, 2, iLastDay, JulianCalendar.CurrentEra))
      Next y
      Console.WriteLine()

      ' Checks five years in each of the eras.
      Dim i As Integer
      For i = 0 To myCal.Eras.Length - 1
         Console.Write("Era {0}:" + ControlChars.Tab, myCal.Eras(i))
         For y = 2001 To 2005
            iLastDay = myCal.GetDaysInMonth(y, 2, myCal.Eras(i))
            Console.Write(ControlChars.Tab + "{0}", myCal.IsLeapDay(y, 2, iLastDay, myCal.Eras(i)))
         Next y
         Console.WriteLine()
      Next i

   End Sub

End Class


'This code produces the following output.

'

'YEAR            2001    2002    2003    2004    2005

'CurrentEra:     False   False   False   True    False

'Era 1:          False   False   False   True    False


Remarks

Unlike the Gregorian calendar, the Julian calendar defines a leap year as a year that is evenly divisible by four with no exceptions. Therefore, the calendar is inaccurate by one day every 128 years. For example, the year 1999 was not a leap year, but the year 2000 was. A common year has 365 days and a leap year has 366 days.

A leap day is a day that occurs only in a leap year. In the Julian calendar, the 29th day of February is the only leap day.

Applies to

See also