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DateTime.DaysInMonth Method

Returns the number of days in the specified month and year.

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

public static int DaysInMonth(
	int year,
	int month


Type: System.Int32

The year.

Type: System.Int32

The month (a number ranging from 1 to 12).

Return Value

Type: System.Int32
The number of days in month for the specified year.
For example, if month equals 2 for February, the return value is 28 or 29 depending upon whether year is a leap year.


month is less than 1 or greater than 12.


year is less than 1 or greater than 9999.

The following example demonstrates the DaysInMonth method.

			const int July = 7;
			const int Feb = 2;

			// daysInJuly gets 31. 
			int daysInJuly = System.DateTime.DaysInMonth(2001, July);

			// daysInFeb gets 28 because the year 1998 was not a leap year. 
			int daysInFeb = System.DateTime.DaysInMonth(1998, Feb);

			// daysInFebLeap gets 29 because the year 1996 was a leap year. 
			int daysInFebLeap = System.DateTime.DaysInMonth(1996, Feb);

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0