DaylightTime Class

// Example of the TimeZone.GetDaylightChanges( int ) method.
using System;
using System.Globalization;

class DaylightChangesDemo
{
    // Get the local time zone and a base local time.
    static TimeZone localZone = TimeZone.CurrentTimeZone;

    static void CreateDaylightTime( int year )
    {
        // Create a DaylightTime object for the specified year.
        DaylightTime daylight = 
            localZone.GetDaylightChanges( year );

        // Display the start and end dates and the time change.
        Console.WriteLine( "{0,-7}{1,-20:yyyy-MM-dd HH:mm}" +
            "{2,-20:yyyy-MM-dd HH:mm}{3}", 
            year, daylight.Start, daylight.End, daylight.Delta );
    } 

    static void Main( )
    {
        const string headFmt = "{0,-7}{1,-20}{2,-20}{3}";

        Console.WriteLine(
            "This example of TimeZone.GetDaylightChanges( int ) " +
            "generates the \nfollowing output, which varies " +
            "depending on the time zone in which \nit is run. The " +
            "example creates DaylightTime objects for specified \n" +
            "years and displays the start and end dates and time " +
            "change for \ndaylight saving time.\n" );

        // Write a message explaining that start dates prior to 1986 
        // in the en-US culture may not be correct.
        if( CultureInfo.CurrentCulture.Name == "en-US" )
        {
            Console.WriteLine(
                "Note: In the [en-US] culture, all start dates are " +
                "calculated from \nthe first Sunday in April, " +
                "based on a standard set in 1986. For \ndates " +
                "prior to 1986, the calculated start date may not " +
                "be accurate." );
        }

        Console.WriteLine( "\nLocal time: {0}\n", 
            localZone.StandardName );

        Console.WriteLine( headFmt, "Year", "Start", "End", "Change" );
        Console.WriteLine( headFmt, "----", "-----", "---", "------" );

        CreateDaylightTime( 1960 );
        CreateDaylightTime( 1970 );
        CreateDaylightTime( 1980 );
        CreateDaylightTime( 1990 );
        CreateDaylightTime( 2000 );
        CreateDaylightTime( 2001 );
        CreateDaylightTime( 2002 );
        CreateDaylightTime( 2003 );
        CreateDaylightTime( 2004 );
        CreateDaylightTime( 2005 );
        CreateDaylightTime( 2020 );
        CreateDaylightTime( 2040 );
    } 
} 

/*
This example of TimeZone.GetDaylightChanges( int ) generates the
following output, which varies depending on the time zone in which
it is run. The example creates DaylightTime objects for specified
years and displays the start and end dates and time change for
daylight saving time.

Note: In the [en-US] culture, all start dates are calculated from
the first Sunday in April, based on a standard set in 1986. For
dates prior to 1986, the calculated start date may not be accurate.

Local time: Pacific Standard Time

Year   Start               End                 Change
----   -----               ---                 ------
1960   1960-04-03 02:00    1960-10-30 02:00    01:00:00
1970   1970-04-05 02:00    1970-10-25 02:00    01:00:00
1980   1980-04-06 02:00    1980-10-26 02:00    01:00:00
1990   1990-04-01 02:00    1990-10-28 02:00    01:00:00
2000   2000-04-02 02:00    2000-10-29 02:00    01:00:00
2001   2001-04-01 02:00    2001-10-28 02:00    01:00:00
2002   2002-04-07 02:00    2002-10-27 02:00    01:00:00
2003   2003-04-06 02:00    2003-10-26 02:00    01:00:00
2004   2004-04-04 02:00    2004-10-31 02:00    01:00:00
2005   2005-04-03 02:00    2005-10-30 02:00    01:00:00
2020   2020-04-05 02:00    2020-10-25 02:00    01:00:00
2040   2040-04-01 02:00    2040-10-28 02:00    01:00:00
*/