Date Time C#

using System;
using System.Globalization;
public class MainClass{
   public static void Main()  {
        DateTime dateGregorian = new DateTime(2009, 1, 13);
        Console.WriteLine(dateGregorian.Day);              
        
        // Create date of 1/13/2009 using Hijri calendar.
        HijriCalendar hijri = new HijriCalendar();
        DateTime dateHijri = new DateTime(1430, 1, 17, hijri);
        // Return day of date created using Hijri calendar.
        Console.WriteLine(dateHijri.Day);                    
        
        // Display day of date in Hijri calendar.
        Console.WriteLine(hijri.GetDayOfMonth(dateHijri));   
   }
}