using System;

using System.Collections.Generic;

using System.Globalization;

using System.Linq;

public class Program

{

    public static IEnumerable<DateTime> OcorrenciasDeHorarios(

        DateTime Inicio, DateTime Final, params string[] Horarios)

    {

        var cultura = new CultureInfo("en-US");

        for (var dia = Inicio; dia <= Final; dia = dia.AddDays(1)) 

        {

            foreach (var diaHorario in Horarios.Select(h => DateTime.Parse(dia.Date.ToString("MM/dd/yyyy") + " " + h)))

            {

                if (diaHorario >= Inicio && diaHorario <= Final)

                    yield return diaHorario;

            }

        }

    }

    public static void Main()

    {

        var lista = OcorrenciasDeHorarios(DateTime.Parse("2017-01-10 01:35:00 PM"), DateTime.Parse("2017-01-12 07:35:00 PM"), "12:50:00 AM", "05:50:00 PM");

        Console.WriteLine(lista.Count());

        foreach (var item in lista) Console.WriteLine(item);

    }

}

​