// C# Extension Method

// Doc: https://csharp-extension.com/en/method/1002269/datetime-startofmonth

​

// @nuget: Z.ExtensionMethods

​

using System;

using System.Globalization;

​

public class Program

{

    public static void Main()

    {

        DateTime todayDate = DateTime.Now;

        Console.WriteLine("Current Date              : {0}", todayDate.ToFullDateTimeString());

        // C# Extension Method: DateTime - StartOfMonth

        DateTime newDate = todayDate.StartOfMonth();

        Console.WriteLine("After calling StartOfMonth: {0}", newDate.ToFullDateTimeString());

    }

}