DateTime, TimeZone, Convert, CSharp, C#

https://docs.microsoft.com/ru-ru/dotnet/standard/datetime/converting-between-time-zones

EF DateTime to Date MS SQL Field

http://stackoverflow.com/questions/5658216/entity-framework-code-first-date-field-creation

http://stackoverflow.com/questions/31912326/how-to-use-date-only-as-data-type-in-entity-framework

System SQL DateTime Function and RowVersion

https://msdn.microsoft.com/ru-ru/library/ms188751.aspx

https://msdn.microsoft.com/ru-ru/library/ms182776.aspx

https://habrahabr.ru/post/61391/

SQL DateTime Types

https://msdn.microsoft.com/en-us/library/ff848733.aspx

https://msdn.microsoft.com/en-us/library/ms187819.aspx

https://msdn.microsoft.com/en-us/library/bb677335.aspx

https://msdn.microsoft.com/en-us/library/bb630289.aspx

https://msdn.microsoft.com/en-us/library/ms182418.aspx

https://msdn.microsoft.com/en-us/library/bb630352.aspx

EntityFrameWork group by some ?

context.Users
    .Where((x.LastLogIn  >= lastWeek) && (x.LastLogIn <= DateTime.Now))
    .GroupBy(x => EntityFunctions.TruncateTime(x.LastLogIn))
    .Select(x => new
    {
        Value = x.Count(),
        // Replace the commented line
        //Day = (DateTime)EntityFunctions.TruncateTime(x.Key)
        // ...with this line
        Day = (DateTime)x.Key
    }).ToList();

  .GroupBy(x => new {Year = x.LastLogIn.Year, Month = x.LastLogIn.Month, Day = x.LastLogIn.Day)

            .Select(x => new

                {
                    Value = x.Count(),
                    Year = x.Key.Year,
                    Month = x.Key.Month,
                    Day = x.Key.Day
                })

GetWeekOfYear()

DateTimeFormatInfo.Calendar

 private int GetWeekOfYear(DateTime DT)
        {
            return

DateTimeFormatInfo.Calendar.GetWeekOfYear(DT, dfi.CalendarWeekRule, dfi.FirstDayOfWeek);

        }

Ticks in long to DateTime

http://stackoverflow.com/questions/1129410/format-from-ticks-to-date

DateTime date = new DateTime(long.Parse(logText));

Or

DateTime logDate = new DateTime(logText);