using System;

using System.Globalization;

​

public class Program

{

    public static void Main()

    {

        //get current month name

        Console.WriteLine(DateTime.Now.ToMonthName());

        Console.WriteLine(DateTime.Now.ToShortMonthName());

        //get previous month name

         var OlderDate= DateTime.ParseExact("22/10/2019","dd/MM/yyyy",CultureInfo.InvariantCulture);

         Console.WriteLine(OlderDate.ToMonthName());

         Console.WriteLine(OlderDate.ToShortMonthName());

    }

}

//create datetime extension class

public static class MonthExtensions

{

    public static string ToMonthName(this DateTime dateTime)

    {

        return CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(dateTime.Month);

    }

​

    public static string ToShortMonthName(this DateTime dateTime)

    {

        return CultureInfo.CurrentCulture.DateTimeFormat.GetAbbreviatedMonthName(dateTime.Month);

    }

}