System.DateTime.AddMonths Method

Returns a new DateTime that adds the specified number of months to the value of this instance.


public DateTime AddMonths (int months)


A number of months. The months parameter can be negative or positive.


An object whose value is the sum of the date and time represented by this instance and months.



The resulting DateTime is less than DateTime.MinValue or greater than DateTime.MaxValue.


The months parameter is less than -120,000 or greater than 120,000


This method does not change the value of this DateTime object. Instead, it returns a new DateTime object whose value is the result of this operation.

The DateTime.AddMonths(int) method calculates the resulting month and year, taking into account leap years and the number of days in a month, then adjusts the day part of the resulting DateTime object. If the resulting day is not a valid day in the resulting month, the last valid day of the resulting month is used. For example, March 31st + 1 month = April 30th. The time-of-day part of the resulting DateTime object remains the same as this instance.


Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0,,