[C# 2.0] Get and Check Daylight Saving Time (DST)

using System.Globalization;

public static DataTable GenerateDST(int startYear, int endYear)
{
  DataTable dt = new DataTable();
  //get the current timezone
  TimeZone oTimeZone = TimeZone.CurrentTimeZone;
  DaylightTime oDST;

  dt.Columns.Add("Year");
  dt.Columns.Add("Start Date");
  dt.Columns.Add("End Date");

  for (int i = startYear; i <= endYear; i++)
  {
    oDST = oTimeZone.GetDaylightChanges(i);
    dt.Rows.Add(oDST.Start.Year, oDST.Start.ToShortDateString(), oDST.End.ToShortDateString());
  }

  oTimeZone = null;
  oDST = null;

  return dt;
}

How to use

GenerateDST(2009, 2016)

Result


PS:Don't forget to set your machine's timezone correctly.

How to check the given DateTime is DST or not?
Here is how in C# 2.0:

DateTime dt = DateTime.Parse("3/8/2009 01:00");
dt.Equals(TimeZone.CurrentTimeZone.GetDaylightChanges(dt.Year).Start)
or
dt.Equals(TimeZone.CurrentTimeZone.GetDaylightChanges(dt.Year).End)

Give the following statements

DateTime dt = DateTime.Parse("3/8/2009 01:00:00");
Console.WriteLine("{0} => {1}", dt.ToString(), dt.Equals(TimeZone.CurrentTimeZone.GetDaylightChanges(dt.Year).Start));

dt = DateTime.Parse("3/8/2009 02:00:00");
Console.WriteLine("{0} => {1}", dt.ToString(), dt.Equals(TimeZone.CurrentTimeZone.GetDaylightChanges(dt.Year).Start));

dt = DateTime.Parse("3/8/2009 03:00:00");
Console.WriteLine("{0} => {1}", dt.ToString(), dt.Equals(TimeZone.CurrentTimeZone.GetDaylightChanges(dt.Year).Start));

dt = DateTime.Parse("11/1/2009 01:00:00");
Console.WriteLine("{0} => {1}", dt.ToString(), dt.Equals(TimeZone.CurrentTimeZone.GetDaylightChanges(dt.Year).End));

dt = DateTime.Parse("11/1/2009 02:00:00");
Console.WriteLine("{0} => {1}", dt.ToString(), dt.Equals(TimeZone.CurrentTimeZone.GetDaylightChanges(dt.Year).End));

dt = DateTime.Parse("11/1/2009 03:00:00");
Console.WriteLine("{0} => {1}", dt.ToString(), dt.Equals(TimeZone.CurrentTimeZone.GetDaylightChanges(dt.Year).End));

Result