Calendar.IsLeapDay Method (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 current era is a leap day.
Assembly: mscorlib (in mscorlib.dll)
'Declaration Public Overridable Function IsLeapDay ( _ year As Integer, _ month As Integer, _ day As Integer _ ) As Boolean
Parameters
- year
- Type: System.Int32
An integer that represents the year.
- month
- Type: System.Int32
A positive integer that represents the month.
- day
- Type: System.Int32
A positive integer that represents the day.
| Exception | Condition |
|---|---|
| ArgumentOutOfRangeException | 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. |
To make up for the difference between the calendar year and the actual time that the earth rotates around the sun or the actual time that the moon rotates around the earth, a leap year has a different number of days from a standard calendar year. Each Calendar implementation defines leap years differently.
A leap day is a day that occurs only in a leap year. For example, in the Gregorian calendar, the 29th day of February is the only leap day.
The following code example compares different implementations of the Calendar class.
Imports System.Globalization Public Class Example Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock) ' Creates an instance of every Calendar type. Dim myCals(6) As Calendar myCals(0) = New GregorianCalendar() myCals(1) = New HebrewCalendar() myCals(2) = New HijriCalendar() myCals(3) = New JapaneseCalendar() myCals(4) = New KoreanCalendar() myCals(5) = New TaiwanCalendar() myCals(6) = New ThaiBuddhistCalendar() ' For each calendar, displays the current year, the number of months in that year, ' and the number of days in each month of that year. Dim i, j, iYear, iMonth, iDay As Integer Dim myDT As DateTime = DateTime.Today For i = 0 To myCals.Length - 1 iYear = myCals(i).GetYear(myDT) outputBlock.Text &= vbCrLf outputBlock.Text += String.Format("{0}, Year: {1}", myCals(i).GetType(), myCals(i).GetYear(myDT)) & vbCrLf outputBlock.Text += String.Format(" MonthsInYear: {0}", myCals(i).GetMonthsInYear(iYear)) & vbCrLf outputBlock.Text += String.Format(" DaysInYear: {0}", myCals(i).GetDaysInYear(iYear)) & vbCrLf outputBlock.Text &= " Days in each month:" & vbCrLf outputBlock.Text &= " " For j = 1 To myCals(i).GetMonthsInYear(iYear) outputBlock.Text += String.Format(" {0,-5}", myCals(i).GetDaysInMonth(iYear, j)) Next j outputBlock.Text &= vbCrLf iMonth = myCals(i).GetMonth(myDT) iDay = myCals(i).GetDayOfMonth(myDT) outputBlock.Text += String.Format(" IsLeapDay: {0}", myCals(i).IsLeapDay(iYear, iMonth, iDay)) & vbCrLf outputBlock.Text += String.Format(" IsLeapMonth: {0}", myCals(i).IsLeapMonth(iYear, iMonth)) & vbCrLf outputBlock.Text += String.Format(" IsLeapYear: {0}", myCals(i).IsLeapYear(iYear)) & vbCrLf Next End Sub End Class 'This code produces the following output. The results vary depending on the date. ' ' System.Globalization.GregorianCalendar, Year: 2002 ' MonthsInYear: 12 ' DaysInYear: 365 ' Days in each month: ' 31 28 31 30 31 30 31 31 30 31 30 31 ' IsLeapDay: False ' IsLeapMonth: False ' IsLeapYear: False ' ' System.Globalization.HebrewCalendar, Year: 5763 ' MonthsInYear: 13 ' DaysInYear: 385 ' Days in each month: ' 30 30 30 29 30 30 29 30 29 30 29 30 29 ' IsLeapDay: False ' IsLeapMonth: False ' IsLeapYear: True ' ' System.Globalization.HijriCalendar, Year: 1423 ' MonthsInYear: 12 ' DaysInYear: 355 ' Days in each month: ' 30 29 30 29 30 29 30 29 30 29 30 30 ' IsLeapDay: False ' IsLeapMonth: False ' IsLeapYear: True ' ' System.Globalization.JapaneseCalendar, Year: 14 ' MonthsInYear: 12 ' DaysInYear: 365 ' Days in each month: ' 31 28 31 30 31 30 31 31 30 31 30 31 ' IsLeapDay: False ' IsLeapMonth: False ' IsLeapYear: False ' ' System.Globalization.JulianCalendar, Year: 2002 ' MonthsInYear: 12 ' DaysInYear: 365 ' Days in each month: ' 31 28 31 30 31 30 31 31 30 31 30 31 ' IsLeapDay: False ' IsLeapMonth: False ' IsLeapYear: False ' ' System.Globalization.KoreanCalendar, Year: 4335 ' MonthsInYear: 12 ' DaysInYear: 365 ' Days in each month: ' 31 28 31 30 31 30 31 31 30 31 30 31 ' IsLeapDay: False ' IsLeapMonth: False ' IsLeapYear: False ' ' System.Globalization.TaiwanCalendar, Year: 91 ' MonthsInYear: 12 ' DaysInYear: 365 ' Days in each month: ' 31 28 31 30 31 30 31 31 30 31 30 31 ' IsLeapDay: False ' IsLeapMonth: False ' IsLeapYear: False ' ' System.Globalization.ThaiBuddhistCalendar, Year: 2545 ' MonthsInYear: 12 ' DaysInYear: 365 ' Days in each month: ' 31 28 31 30 31 30 31 31 30 31 30 31 ' IsLeapDay: False ' IsLeapMonth: False ' IsLeapYear: False