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
Assemblies:   System.Globalization (in System.Globalization.dll)
  mscorlib (in mscorlib.dll)

abstract IsLeapMonth : 
        year:int * 
        month:int -> bool  
override IsLeapMonth : 
        year:int * 
        month:int -> bool


Type: System.Int32

An integer that represents the year.

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.


year is outside the range supported by the calendar.


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.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Was this page helpful?
(1500 characters remaining)
Thank you for your feedback
© 2014 Microsoft