GregorianCalendar.IsLeapDay Method (Int32, Int32, Int32, Int32)
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Determines whether the specified date in the specified era is a leap day.
Assembly: mscorlib (in mscorlib.dll)
'Declaration Public Overrides Function IsLeapDay ( _ year As Integer, _ month As Integer, _ day As Integer, _ era As Integer _ ) As Boolean
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.
| 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. |
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.
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