GregorianCalendar.IsLeapDay Method (Int32, Int32, Int32, Int32)
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Determines whether the specified date in the specified era is a leap day.
Namespace: System.Globalization
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Overrides Function IsLeapDay ( _
year As Integer, _
month As Integer, _
day As Integer, _
era As Integer _
) As Boolean
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.
Exceptions
| Exception | Condition |
|---|---|
| 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. |
Remarks
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.
Examples
The following code example calls IsLeapDay for the last day of the second month (February) for five years in each of the eras.
Imports System.Globalization
Public Class Example
Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
' Creates and initializes a GregorianCalendar.
Dim myCal As New GregorianCalendar()
' Creates a holder for the last day of the second month (February).
Dim iLastDay As Integer
' Displays the header.
outputBlock.Text &= "YEAR" + ControlChars.Tab
Dim y As Integer
For y = 2001 To 2005
outputBlock.Text += String.Format(ControlChars.Tab + "{0}", y)
Next
outputBlock.Text &= vbCrLf
' Checks five years in the current era.
outputBlock.Text &= "CurrentEra:"
For y = 2001 To 2005
iLastDay = myCal.GetDaysInMonth(y, 2, GregorianCalendar.CurrentEra)
outputBlock.Text += String.Format(ControlChars.Tab + "{0}", myCal.IsLeapDay(y, 2, iLastDay, GregorianCalendar.CurrentEra))
Next
outputBlock.Text &= vbCrLf
' Checks five years in each of the eras.
For i As Integer = 0 To myCal.Eras.Length - 1
outputBlock.Text += String.Format("Era {0}:" + ControlChars.Tab, myCal.Eras(i))
For y = 2001 To 2005
iLastDay = myCal.GetDaysInMonth(y, 2, myCal.Eras(i))
outputBlock.Text += String.Format(ControlChars.Tab + "{0}", myCal.IsLeapDay(y, 2, iLastDay, myCal.Eras(i)))
Next
outputBlock.Text &= vbCrLf
Next
End Sub
End Class
' This example 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 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
*/
Version Information
Silverlight
Supported in: 5, 4, 3
Silverlight for Windows Phone
Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0
XNA Framework
Supported in: Xbox 360, Windows Phone OS 7.0
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.