public class HeatMapViewModel
{
    public decimal? Latitude2 { get; set; }
    public decimal? Longitude2 { get; set; }
    public int coeff = 2;
    public int Difference;
    public DateTime Date { get; set; }
}

public List<HeatMapViewModel> GetStops()
{
    using (TraxgoDB ctx = new TraxgoDB())
    {
        List<HeatMapViewModel> items = new List<HeatMapViewModel>();

        var firstitem = ctx.Logging.Where(x => x.Datatype == Datatype.Start).AsEnumerable().FirstOrDefault();

        var midnight = new DateTime(firstitem.CurrentDateTime.Year, firstitem.CurrentDateTime.Month, firstitem.CurrentDateTime.Day, 00, 00, 00);
        TimeSpan difference = (firstitem.CurrentDateTime - midnight);
        var difference_after_midnight = (int)difference.TotalMinutes;

        items.Add(new HeatMapViewModel
        {
            Latitude2 = firstitem.Latitude,
            Longitude2 = firstitem.Longitude,
            Difference = difference_after_midnight,
            Date = firstitem.CurrentDateTime
        });

       var lastItem = ctx.Logging.Where(x => x.Datatype == Datatype.Stop).AsEnumerable().LastOrDefault();
       var before_midnight = new DateTime(lastItem.CurrentDateTime.Year, lastItem.CurrentDateTime.Month, lastItem.CurrentDateTime.Day, 23, 59, 00);
       TimeSpan difference_before = (before_midnight - lastItem.CurrentDateTime);
       var difference_before_midnight = (int)difference_before.TotalMinutes;

       items.Add(new HeatMapViewModel
       {
            Latitude2 = lastItem.Latitude,
            Longitude2 = lastItem.Longitude,
            Difference = difference_before_midnight,
            Date = firstitem.CurrentDateTime
        });

        var allitems = ctx.Logging;
        var filteredQuery = allitems.Where(x => x.Datatype == Datatype.Start || x.Datatype == Datatype.Stop).OrderByDescending(x => x.LogID).ToList();

        for (int i = 1; i < filteredQuery.Count; i++)
        {
            if (filteredQuery[i].Datatype == Datatype.Stop && filteredQuery[i - 1].Datatype == Datatype.Start)
            {
                TimeSpan differenceTicks = filteredQuery[i - 1].CurrentDateTime - filteredQuery[i].CurrentDateTime;

                items.Add(new HeatMapViewModel
                {
                    Latitude2 = filteredQuery[i].Latitude,
                    Longitude2 = filteredQuery[i].Longitude,
                    Difference = (int)differenceTicks.TotalMinutes,
                    Date = firstitem.CurrentDateTime
                });
            }
        }
        return items;
    }
}