C# DateTime DaysInMonth

Description

DateTime DaysInMonth returns the number of days in the specified month and year.

Syntax

DateTime.DaysInMonth has the following syntax.


public static int DaysInMonth(
  int year,
  int month
)

Parameters

DateTime.DaysInMonth has the following parameters.

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

Returns

DateTime.DaysInMonth method returns 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.

Example

The following example demonstrates how to use the DaysInMonth method to determine the number of days in July 2001, February 1998 (a non-leap year), and February 1996 (a leap year).


//from   w w  w . jav a  2 s.c  o  m
using System;

class Example
{
  static void Main()
  {
    const int July = 7;
    const int Feb = 2;

    int daysInJuly = System.DateTime.DaysInMonth(2001, July);
        Console.WriteLine(daysInJuly);

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

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

The code above generates the following result.

Example 2

The following example displays the number of days in each month of a year specified in an integer array.


using System;//w  w  w  .j a  va2s .c om
using System.Globalization;

public class Example
{
   public static void Main()
   {
      int[] years = { 2012, 2014 };
      DateTimeFormatInfo dtfi = DateTimeFormatInfo.CurrentInfo;
      Console.WriteLine("Days in the Month for the {0} culture " +
                        "using the {1} calendar\n", 
                        CultureInfo.CurrentCulture.Name, 
                        dtfi.Calendar.GetType().Name.Replace("Calendar", ""));
      Console.WriteLine("{0,-10}{1,-15}{2,4}\n", "Year", "Month", "Days");

      foreach (var year in years) {
         for (int ctr = 0; ctr <= dtfi.MonthNames.Length - 1; ctr++) {
            if (String.IsNullOrEmpty(dtfi.MonthNames[ctr]))  
               continue;

            Console.WriteLine("{0,-10}{1,-15}{2,4}", year, 
                              dtfi.MonthNames[ctr], 
                              DateTime.DaysInMonth(year, ctr + 1));
         }
         Console.WriteLine(); 
      }
   }
}

The code above generates the following result.