هل يمكنك شرح الكلاس التالي بالتفصيل    using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Net.Sockets;


namespace MrSales.MrSControls
{
  public static class DateTimeExtensions
  {
    public static DateTime smethod_0()
    {
      DateTime dateTime1 = DateTime.MinValue;
      string[] source = new string[10]
      {
        "nist1-ny.ustiming.org",
        "nist1-nj.ustiming.org",
        "nist1-pa.ustiming.org",
        "time-a.nist.gov",
        "time-b.nist.gov",
        "nist1.aol-va.symmetricom.com",
        "nist1.columbiacountyga.gov",
        "nist1-chi.ustiming.org",
        "nist.expertsmi.com",
        "nist.netservicesgroup.com"
      };
      Random random_0 = new Random();
      DateTime dateTime2;
      foreach (string hostname in ((IEnumerable<string>) source).OrderBy<string, double>((Func<string, double>) (s => random_0.NextDouble())).Take<string>(5))
      {
        try
        {
          string str = string.Empty;
          using (StreamReader streamReader = new StreamReader((Stream) new TcpClient(hostname, 13).GetStream()))
            str = streamReader.ReadToEnd();
          if (!string.IsNullOrEmpty(str))
          {
            string[] strArray1 = str.Split(' ');
            if (strArray1.Length >= 6)
            {
              if (strArray1[5] == "0")
              {
                string[] strArray2 = strArray1[1].Split('-');
                string[] strArray3 = strArray1[2].Split(':');
                dateTime1 = new DateTime(Convert.ToInt32(strArray2[0]) + 2000, Convert.ToInt32(strArray2[1]), Convert.ToInt32(strArray2[2]), Convert.ToInt32(strArray3[0]), Convert.ToInt32(strArray3[1]), Convert.ToInt32(strArray3[2])).ToLocalTime();
                dateTime2 = dateTime1;
                goto label_18;
              }
            }
          }
        }
        catch
        {
        }
      }
      dateTime2 = dateTime1;
label_18:
      return dateTime2;
    }

    public static DateTime NullHandling(this DateTime dt) => dt;

    public static DateTime StartOfDay(this DateTime dt)
    {
      dt = dt.NullHandling();
      return new DateTime(dt.Year, dt.Month, dt.Day, 0, 0, 0);
    }

    public static DateTime EndOfDay(this DateTime dt)
    {
      dt = dt.NullHandling();
      return new DateTime(dt.Year, dt.Month, dt.Day, 23, 59, 59).AddMilliseconds(999.0);
    }

    public static DateTime StartOfWeek(this DateTime dt, DayOfWeek startOfWeek = DayOfWeek.Saturday)
    {
      dt = dt.NullHandling();
      startOfWeek = SysSettings.StartOfWeek;
      int num = dt.DayOfWeek - startOfWeek;
      if (num < 0)
        num += 7;
      return dt.AddDays((double) (-1 * num)).StartOfDay();
    }

    public static DateTime EndOfWeek(this DateTime dt, DayOfWeek endOfWeek = DayOfWeek.Friday)
    {
      dt = dt.NullHandling();
      endOfWeek = SysSettings.EndOfWeek;
      DateTime dateTime;
      if (dt.DayOfWeek != endOfWeek)
      {
        int num = dt.EndOfDay().DayOfWeek - endOfWeek;
        dateTime = dt.AddDays((double) (8 - -1 * num)).EndOfDay();
      }
      else
        dateTime = dt.Date.EndOfDay();
      return dateTime;
    }

    public static DateTime FirstDayOfYear(this DateTime dt)
    {
      dt = dt.NullHandling();
      return new DateTime(dt.Year, 1, 1).StartOfDay();
    }

    public static DateTime LastDayOfYear(this DateTime dt)
    {
      dt = dt.NullHandling();
      return new DateTime(dt.Year, 12, 31).EndOfDay();
    }

    public static DateTime FirstDayOfMonth(this DateTime dt)
    {
      dt = dt.NullHandling();
      return new DateTime(dt.Year, dt.Month, 1).StartOfDay();
    }

    public static DateTime LastDayOfMonth(this DateTime dt)
    {
      dt = dt.NullHandling();
      return new DateTime(dt.Year, dt.Month, 1).AddMonths(1).AddDays(-1.0).EndOfDay();
    }

    public static DateTime DateBuilding(this DateTime Year, DateTime Month, DateTime Day)
    {
      Year = Year.NullHandling();
      Day = Day.NullHandling();
      Month = Month.NullHandling();
      return new DateTime(Year.Year, Month.Month, Day.Day);
    }

    public static DateTime GetCustomDayInCustomYear_StartOfDay(this DateTime Year, DateTime Day)
    {
      Year = Year.NullHandling();
      Day = Day.NullHandling();
      return new DateTime(Year.Year, Day.Month, Day.Day).StartOfDay();
    }

    public static DateTime GetCustomDayInCustomYear_EndOfDay(this DateTime Year, DateTime Day)
    {
      Year = Year.NullHandling();
      Day = Day.NullHandling();
      return new DateTime(Year.Year, Day.Month, Day.Day).EndOfDay();
    }

    public static string ToMonthName(this DateTime dateTime)
    {
      return CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(dateTime.Month);
    }

    public static string ToShortMonthName(this DateTime dateTime)
    {
      return CultureInfo.CurrentCulture.DateTimeFormat.GetAbbreviatedMonthName(dateTime.Month);
    }

    public static string getDayOfWeekName(this DateTime dateTime)
    {
      return dateTime.ToString("dddd", (IFormatProvider) new CultureInfo("en"));
    }
  }
}