using System;

​

public class Program

{

    public static void Main()

    {

        DateTime dt = DateTime.Now;

        //Write(dt, TimeZoneInfo.Local.Id, TimeZoneInfo.Local.Id);

        //Write(dt, TimeZoneInfo.Local.Id, "Atlantic Standard Time");

        //Write(dt, TimeZoneInfo.Local.Id, "Eastern Standard Time");

        //Write(dt, TimeZoneInfo.Local.Id, "US Eastern Standard Time");

        //Write(dt, TimeZoneInfo.Local.Id, "Central Standard Time");

        //Write(dt, TimeZoneInfo.Local.Id, "Mountain Standard Time");

        //Write(dt, TimeZoneInfo.Local.Id, "US Mountain Standard Time");

        //Write(dt, TimeZoneInfo.Local.Id, "Pacific Standard Time");    

        //Write(dt, TimeZoneInfo.Local.Id, "Alaskan Standard Time");

        //Write(dt, TimeZoneInfo.Local.Id, "Hawaiian Standard Time");

        TimeZoneInfo centralTimeZone, easternTimeZone;

        // UTC -> Central -> Eastern (Supports DST)

        //dt = new DateTime(2017, 1, 20, 10, 43, 23);

        //Write(dt, TimeZoneInfo.Local.Id, "Central Standard Time");

        //centralTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time");

        //easternTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");

        //dt = TimeZoneInfo.ConvertTime(dt, centralTimeZone);

        //Write(dt, "Central Standard Time", "Eastern Standard Time");

        //dt = new DateTime(2017, 7, 20, 10, 43, 23);

        //Write(dt, TimeZoneInfo.Local.Id, "Central Standard Time");

        //centralTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time");

        //easternTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");

        //dt = TimeZoneInfo.ConvertTime(dt, centralTimeZone);

        //Write(dt, "Central Standard Time", "Eastern Standard Time");

        // UTC -> Central -> US Mountain (Arizona No DST)

        dt = new DateTime(2017, 1, 20, 10, 43, 23);

        Write(dt, TimeZoneInfo.Local.Id, "Central Standard Time");

        centralTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time");

        easternTimeZone = TimeZoneInfo.FindSystemTimeZoneById("US Mountain Standard Time");

        dt = TimeZoneInfo.ConvertTime(dt, centralTimeZone);

        Write(dt, "Central Standard Time", "US Mountain Standard Time");

        dt = new DateTime(2017, 7, 20, 10, 43, 23);

        Write(dt, TimeZoneInfo.Local.Id, "Central Standard Time");

        centralTimeZone = TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time");

        easternTimeZone = TimeZoneInfo.FindSystemTimeZoneById("US Mountain Standard Time");

        dt = TimeZoneInfo.ConvertTime(dt, centralTimeZone);

        Write(dt, "Central Standard Time", "US Mountain Standard Time");

    }

    static void Write(DateTime datetime, string sourceTimeZoneId, string destinationTimeZoneId)

    {       

        TimeZoneInfo sourceTimeZone = TimeZoneInfo.FindSystemTimeZoneById(sourceTimeZoneId);

        TimeZoneInfo destinationTimeZone = TimeZoneInfo.FindSystemTimeZoneById(destinationTimeZoneId);

        DateTime dt = TimeZoneInfo.ConvertTime(datetime, sourceTimeZone, destinationTimeZone);

        Console.WriteLine();

        Console.WriteLine("Source TZI");

        Console.WriteLine("  - Id              : " + sourceTimeZone.Id);

        Console.WriteLine("  - DisplayName     : " + sourceTimeZone.DisplayName);

        Console.WriteLine("  - StandardName    : " + sourceTimeZone.StandardName);

        Console.WriteLine("  - DaylightName    : " + sourceTimeZone.DaylightName);

        Console.WriteLine("  - BaseUtcOffset   : " + sourceTimeZone.BaseUtcOffset);

        Console.WriteLine("  - SupportsDST     : " + sourceTimeZone.SupportsDaylightSavingTime);

        Console.WriteLine("Destination");

        Console.WriteLine("  - Id              : " + destinationTimeZone.Id);

        Console.WriteLine("  - DisplayName     : " + destinationTimeZone.DisplayName);

        Console.WriteLine("  - StandardName    : " + destinationTimeZone.StandardName);

        Console.WriteLine("  - DaylightName    : " + destinationTimeZone.DaylightName);

        Console.WriteLine("  - BaseUtcOffset   : " + destinationTimeZone.BaseUtcOffset);

        Console.WriteLine("  - SupportsDST     : " + destinationTimeZone.SupportsDaylightSavingTime);

        Console.WriteLine("DateTime");

        Console.WriteLine("  - Starting Value  : " + datetime.ToString());      

        Console.WriteLine("  - Starting Kind   : " + datetime.Kind.ToString());

        Console.WriteLine("  - Converted       : " + dt.ToString());

        Console.WriteLine("  - Kind            : " + dt.Kind.ToString());

        Console.WriteLine("  - IsAmbiguousTime : " + destinationTimeZone.IsAmbiguousTime(dt));

        Console.WriteLine("  - IsDST           : " + destinationTimeZone.IsDaylightSavingTime(dt));

        Console.WriteLine("  - IsInvalidTime   : " + destinationTimeZone.IsInvalidTime(dt));

    }

}