using System;

public static class Program

{

    //AI Copilot Improved Code

    public static DateTime RoundToNearestMinuteProper(this DateTime dt, int rndmin, RoundingDirection directn)

    {

        if (rndmin <= 0)

            return dt;

​

        long ticksPerInterval = TimeSpan.FromMinutes(rndmin).Ticks;

        long modTicks = dt.Ticks % ticksPerInterval;

​

        long delta = 0;

        switch (directn)

        {

            case RoundingDirection.Up:

                delta = (modTicks == 0) ? 0 : ticksPerInterval - modTicks;

                break;

            case RoundingDirection.Down:

                delta = -modTicks;

                break;

            case RoundingDirection.Nearest:

                delta = (modTicks > ticksPerInterval / 2) ? ticksPerInterval - modTicks : -modTicks;

                break;

            default:

                delta = 0; // Handle unsupported rounding directions

                break;

        }

​

        return new DateTime(dt.Ticks + delta, dt.Kind);

    }

​

     public enum RoundingDirection

     {

          Up,

          Down,

          Nearest

     }

​

    public static void Main()

    {

      //var dt = new DateTime(2001, 1, 1, 0, 0, 0, 000);

      //var dt = new DateTime(2018, 08, 03, 10, 7, 30, 000); //8/3/2018 10:00:00 AM Nearest, re 15/2 = 7.5 mins or 7 mins and 30 secs

      var dt = new DateTime(2018, 08, 03, 10, 7, 31, 000); //8/3/2018 10:15:00 AM Nearest

​

      Console.WriteLine(dt.RoundToNearestMinuteProper(15, RoundingDirection.Up)); 

      Console.WriteLine(dt.RoundToNearestMinuteProper(15, RoundingDirection.Down)); 

      Console.WriteLine(dt.RoundToNearestMinuteProper(15, RoundingDirection.Nearest)); 

    }

}