using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var lastRun = new DateTime(2020, 05, 01);

        var runHours = new (int Start, int Length)[] { 

            (0, 6),

            (6, 5),

            (11, 4),

            (15, 3),

            (18, 12),

        };

​

        var daysToRun = DateTime.Today.Subtract(lastRun).Days;

        var datesToRun = Enumerable.Range(0, daysToRun).Select(d => lastRun.AddDays(d));

        var timesToRun = datesToRun.Select(d => runHours.Select(h => new {

            Start = d.AddHours(h.Start),

            End = d.AddHours(h.Start).AddHours(h.Length)

        }));

        Console.WriteLine($"Created {timesToRun.Sum(t => t.Count())} timeslots\n");

        var commandTemplate = @"REM C:\Source\BottomlineManualRun\Bottomline.exe ""{0:yyyy-MM-dd HH:mm:ss}"" ""{1:yyyy-MM-dd HH:mm:ss}""";

        foreach (var dayToRun in timesToRun) {

            var commands = dayToRun

                .Where(t => t.Start.Hour != 0)

                .Select(t => String.Format(commandTemplate, t.Start, t.End));

            Console.WriteLine(String.Join("\n", commands));

            Console.WriteLine();

        }

        var offHourSlots = timesToRun.SelectMany(t => t).Where(t => t.Start.Hour == 0).Select(t => String.Format(commandTemplate, t.Start, t.End));

        Console.WriteLine(String.Join("\n", offHourSlots));

    }

}