using System;

using System.Collections.Generic;

using System.Data;

using System.Data.SqlClient;

using System.Linq;

public class Program

{

    public class Forecast

    {

       public int LocationId;

       public int DepartmentId;

       public DateTime StartTime;

       public DateTime EndTime;

       public int CountOfEmployees;

    }

    public static void Main()

    {

            var forecast = new Forecast[16];

            forecast[0] = new Forecast { LocationId = 1, DepartmentId = 1, StartTime = new DateTime(2018, 10, 1, 06, 00, 00), EndTime = new DateTime(2018, 10, 01, 06, 15, 0), CountOfEmployees = 2 };

            forecast[1] = new Forecast { LocationId = 1, DepartmentId = 1, StartTime = new DateTime(2018, 10, 1, 06, 15, 00), EndTime = new DateTime(2018, 10, 01, 06, 30, 0), CountOfEmployees = 1 };

            forecast[2] = new Forecast { LocationId = 1, DepartmentId = 1, StartTime = new DateTime(2018, 10, 1, 06, 30, 00), EndTime = new DateTime(2018, 10, 01, 06, 45, 0), CountOfEmployees = 3 };

            forecast[3] = new Forecast { LocationId = 1, DepartmentId = 1, StartTime = new DateTime(2018, 10, 1, 06, 45, 00), EndTime = new DateTime(2018, 10, 01, 07, 00, 0), CountOfEmployees = 1 };

            forecast[4] = new Forecast { LocationId = 1, DepartmentId = 1, StartTime = new DateTime(2018, 10, 1, 07, 00, 00), EndTime = new DateTime(2018, 10, 01, 07, 15, 0), CountOfEmployees = 2 };

            forecast[5] = new Forecast { LocationId = 1, DepartmentId = 1, StartTime = new DateTime(2018, 10, 1, 07, 15, 00), EndTime = new DateTime(2018, 10, 01, 07, 30, 0), CountOfEmployees = 2 };

            forecast[6] = new Forecast { LocationId = 1, DepartmentId = 1, StartTime = new DateTime(2018, 10, 1, 07, 30, 00), EndTime = new DateTime(2018, 10, 01, 07, 45, 0), CountOfEmployees = 5 };

            forecast[7] = new Forecast { LocationId = 1, DepartmentId = 1, StartTime = new DateTime(2018, 10, 1, 07, 45, 00), EndTime = new DateTime(2018, 10, 01, 08, 00, 0), CountOfEmployees = 3 };

            forecast[8] = new Forecast { LocationId = 2, DepartmentId = 2, StartTime = new DateTime(2018, 10, 1, 06, 00, 00), EndTime = new DateTime(2018, 10, 01, 06, 15, 0), CountOfEmployees = 2 };

            forecast[9] = new Forecast { LocationId = 2, DepartmentId = 2, StartTime = new DateTime(2018, 10, 1, 06, 15, 00), EndTime = new DateTime(2018, 10, 01, 06, 30, 0), CountOfEmployees = 1 };

            forecast[10] = new Forecast { LocationId = 2, DepartmentId = 2, StartTime = new DateTime(2018, 10, 1, 06, 30, 00), EndTime = new DateTime(2018, 10, 01, 06, 45, 0), CountOfEmployees = 3 };

            forecast[11] = new Forecast { LocationId = 2, DepartmentId = 2, StartTime = new DateTime(2018, 10, 1, 06, 45, 00), EndTime = new DateTime(2018, 10, 01, 07, 00, 0), CountOfEmployees = 1 };

            forecast[12] = new Forecast { LocationId = 2, DepartmentId = 2, StartTime = new DateTime(2018, 10, 1, 07, 00, 00), EndTime = new DateTime(2018, 10, 01, 07, 15, 0), CountOfEmployees = 2 };

            forecast[13] = new Forecast { LocationId = 2, DepartmentId = 2, StartTime = new DateTime(2018, 10, 1, 07, 15, 00), EndTime = new DateTime(2018, 10, 01, 07, 30, 0), CountOfEmployees = 2 };

            forecast[14] = new Forecast { LocationId = 2, DepartmentId = 2, StartTime = new DateTime(2018, 10, 1, 07, 30, 00), EndTime = new DateTime(2018, 10, 01, 07, 45, 0), CountOfEmployees = 5 };

            forecast[15] = new Forecast { LocationId = 2, DepartmentId = 2, StartTime = new DateTime(2018, 10, 1, 07, 45, 00), EndTime = new DateTime(2018, 10, 01, 08, 00, 0), CountOfEmployees = 3 };

 var result = forecast

.GroupBy(_ => new {

    _.LocationId,

    StartTime = new DateTime(_.StartTime.Year,

                              _.StartTime.Month,

                              _.StartTime.Day,

                              _.StartTime.Hour,0,0,0),

    EndTime = new DateTime(_.StartTime.Year,

                              _.StartTime.Month,

                              _.StartTime.Day,

                              _.StartTime.Hour + 1, 0, 0, 0)

})

.Select(x => new {

    x.Key.LocationId,

    x.Key.StartTime,

    x.Key.EndTime,

    CountOfEmployees = x.Sum(y=>y.CountOfEmployees)});

  foreach (var item in result)

                Console.WriteLine(string.Format("LocationId : {0} StartTime : {1} EndTime : {2}  CountOfEmployees : {3}", item.LocationId, item.StartTime, item.EndTime, item.CountOfEmployees));

    }

}

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