using System;

using System.Collections.Generic;

using System.Linq;

​

​

public class Program

{

    public class DatetimeInterval

    {

        public DateTime From { get; set; }

        public DateTime To { get; set; }

​

        public DatetimeInterval(DateTime from, DateTime to)

        {

            From = from;

            To = to;

        }

    }

​

public class OverlapComparer : EqualityComparer<DatetimeInterval>

{

    public override bool Equals(DatetimeInterval oldRegistation, DatetimeInterval newRegistration)

    {

            return oldRegistation.From >= newRegistration.To && oldRegistation.To <= newRegistration.From;

    }

​

        public override int GetHashCode(DatetimeInterval obj)

        {

            return obj.GetHashCode();

        }

}   

​

    public static void Main()

    {

        var start0A = new DateTime(2008, 5, 1, 8, 30, 52);

        var end0A = new DateTime(2012, 5, 1, 8, 30, 52);

        var dateTimeInterval0 = new DatetimeInterval(start0A, end0A);

        var start1A = new DateTime(2014, 5, 1, 8, 30, 52);

        var end1A = new DateTime(2016, 5, 1, 8, 30, 52);

        var dateTimeInterval1 = new DatetimeInterval(start1A, end1A);       

        var start2A = new DateTime(2016, 5, 1, 8, 30, 52);

        var end2A = new DateTime(2020, 5, 1, 8, 30, 52);

        var dateTimeInterval2 = new DatetimeInterval(start2A, end2A);   

        var oldDateTimes = new List<DatetimeInterval>() {dateTimeInterval0, dateTimeInterval1, dateTimeInterval2};

​

        var start0B = new DateTime(2010, 5, 1, 8, 30, 52);

        var end0B = new DateTime(2014, 5, 1, 8, 30, 52);

        var newDateTimeInterval0 = new DatetimeInterval(start0B, end0B);

        var start1B = new DateTime(2015, 5, 1, 8, 30, 52);

        var end1B = new DateTime(2018, 5, 1, 8, 30, 52);        

        var newDateTimeInterval1 = new DatetimeInterval(start1B, end1B);

        var newDateTimeChunk0 = new List<DatetimeInterval>() {newDateTimeInterval0, newDateTimeInterval1};

​

        var start2C = new DateTime(2007, 5, 1, 8, 30, 52);

        var end2C = new DateTime(2015, 5, 1, 8, 30, 52);

        var newDateTimeInterval2 = new DatetimeInterval(start2C, end2C);

        var start3D = new DateTime(2012, 5, 1, 8, 30, 52);

        var end3D = new DateTime(2013, 5, 1, 8, 30, 52);        

        var newDateTimeInterval3 = new DatetimeInterval(start3D, end3D);

        var newDateTimeChunk1 = new List<DatetimeInterval>() {newDateTimeInterval2, newDateTimeInterval3};

​

        var newDateTimeChunks = new List<List<DatetimeInterval>> () {newDateTimeChunk0, newDateTimeChunk1}; 

        foreach (List<DatetimeInterval> chunkedRegistration in newDateTimeChunks)

        {

            IEnumerable<DatetimeInterval> overLappingOldRegistrations = oldDateTimes.Intersect(chunkedRegistration, new OverlapComparer());

            Console.WriteLine("new: ");

            foreach (DatetimeInterval Registration in chunkedRegistration)

            {

                Console.Write("("+Registration.From+","+Registration.To+") ");

            }

            Console.WriteLine("Overlapped by:");

            foreach (DatetimeInterval Registration in overLappingOldRegistrations)

            {

                Console.Write("("+Registration.From+","+Registration.To+") ");

            }

        }

    }

}