GregorianCalendar.IsLeapDay Method (Int32, Int32, Int32, Int32)

July 28, 2014

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

Namespace:  System.Globalization
Assembly:  mscorlib (in mscorlib.dll)

public override bool IsLeapDay(
	int year,
	int month,
	int day,
	int era
)

Parameters

year
Type: System.Int32
An integer that represents the year.
month
Type: System.Int32
An integer from 1 to 12 that represents the month.
day
Type: System.Int32
An integer from 1 to 31 that represents the day.
era
Type: System.Int32
An integer that represents the era.

Return Value

Type: System.Boolean
true if the specified day is a leap day; otherwise, false.

ExceptionCondition
ArgumentOutOfRangeException

era is outside the range supported by the calendar.

-or-

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.

A leap year in the Gregorian calendar is defined as a year that is evenly divisible by four, except if it is divisible by 100. However, years that are divisible by 400 are leap years. For example, the year 1900 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 Gregorian calendar, the 29th day of February is the only leap day.

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


using System;
using System.Globalization;


public class Example
{

   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {

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

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

      // Displays the header.
      outputBlock.Text += "YEAR\t";
      for (int y = 2001; y <= 2005; y++)
         outputBlock.Text += String.Format("\t{0}", y);
      outputBlock.Text += "\n";

      // Checks five years in the current era.
      outputBlock.Text += "CurrentEra:";
      for (int y = 2001; y <= 2005; y++)
      {
         iLastDay = myCal.GetDaysInMonth(y, 2, GregorianCalendar.CurrentEra);
         outputBlock.Text += String.Format("\t{0}", myCal.IsLeapDay(y, 2, iLastDay, GregorianCalendar.CurrentEra));
      }
      outputBlock.Text += "\n";

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

   }

}

/*
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

*/


Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

Show:
© 2014 Microsoft