Calendar.IsLeapMonth Method (Int32, Int32)

 

Determines whether the specified month in the specified year in the current era is a leap month.

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

Public Overridable Function IsLeapMonth (
	year As Integer,
	month 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.

Return Value

Type: System.Boolean

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

Exception Condition
ArgumentOutOfRangeException

year is outside the range supported by the calendar.

-or-

month 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 month is an entire month that occurs only in a leap year. For example, in the Hebrew calendar, Adar Beit is the only leap month.

The following code example compares different implementations of the Calendar class.

Imports System
Imports System.Globalization


Public Class SamplesCalendar   

   Public Shared Sub Main()

      ' Creates an instance of every Calendar type.
      Dim myCals(7) As Calendar
      myCals(0) = New GregorianCalendar()
      myCals(1) = New HebrewCalendar()
      myCals(2) = New HijriCalendar()
      myCals(3) = New JapaneseCalendar()
      myCals(4) = New JulianCalendar()
      myCals(5) = New KoreanCalendar()
      myCals(6) = New TaiwanCalendar()
      myCals(7) = 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)
         Console.WriteLine()
         Console.WriteLine("{0}, Year: {1}", myCals(i).GetType(), myCals(i).GetYear(myDT))
         Console.WriteLine("   MonthsInYear: {0}", myCals(i).GetMonthsInYear(iYear))
         Console.WriteLine("   DaysInYear: {0}", myCals(i).GetDaysInYear(iYear))
         Console.WriteLine("   Days in each month:")
         Console.Write("      ")

         For j = 1 To myCals(i).GetMonthsInYear(iYear)
            Console.Write(" {0,-5}", myCals(i).GetDaysInMonth(iYear, j))
         Next j
         Console.WriteLine()

         iMonth = myCals(i).GetMonth(myDT)
         iDay = myCals(i).GetDayOfMonth(myDT)
         Console.WriteLine("   IsLeapDay:   {0}", myCals(i).IsLeapDay(iYear, iMonth, iDay))
         Console.WriteLine("   IsLeapMonth: {0}", myCals(i).IsLeapMonth(iYear, iMonth))
         Console.WriteLine("   IsLeapYear:  {0}", myCals(i).IsLeapYear(iYear))
      Next i 

   End Sub 'Main

End Class 'SamplesCalendar 


'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

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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