using System;

public class Program

{

    public static void Main()

    {

        var scheduleDay = 23;

        OldAlgorithm(new DateTime(2024, 6, 24), scheduleDay);

        NewAlgorithm(new DateTime(2024, 6, 24), scheduleDay);

    }

    public static void OldAlgorithm(DateTime today, int scheduleDay)

    {

        int current;

        int previous;

        //old algorithm

        current = today.Month;

        previous = current-1;

​

        Console.WriteLine("Existing algorithm");

        Console.WriteLine(current);

        Console.WriteLine(previous);

    }

    public static void NewAlgorithm(DateTime today, int scheduleDay)

    {

        int current;

        int previous;

        if (today.Day < scheduleDay)

        {

            current = today.Month - 1;

            previous = today.Month - 2;

        }

        else 

        {

            current = today.Month;

            previous = today.Month - 1;         

        }

        Console.WriteLine("New algorithm");

        Console.WriteLine(current);

        Console.WriteLine(previous);    

    }

}