using System;

public class Program

{

    public static void Main()

    {

        var utcDateTime = new DateTime(2018,12,25,09,00,00,DateTimeKind.Utc);

        Console.WriteLine("Time difference when DST is Off");

        Console.WriteLine("Time in UTC: "+utcDateTime.ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Newfoundland

        Console.WriteLine("Time in Newfoundland: "+ConvertToRestaurantTime(utcDateTime, "Newfoundland Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Atlantic 

        Console.WriteLine("Time in Atlantic: "+ConvertToRestaurantTime(utcDateTime, "Atlantic Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Eastern

        Console.WriteLine("Time in Eastern: "+ConvertToRestaurantTime(utcDateTime, "Eastern Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Central

        Console.WriteLine("Time in Central: "+ConvertToRestaurantTime(utcDateTime, "Central Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Moutain

        Console.WriteLine("Time in Mountain: "+ConvertToRestaurantTime(utcDateTime, "Mountain Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Saskatchewan

        Console.WriteLine("Time in Saskatchewan: "+ConvertToRestaurantTime(utcDateTime, "Canada Central Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Pacific

        Console.WriteLine("Time in Pacific: "+ConvertToRestaurantTime(utcDateTime, "Pacific Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        ///////////////////////////////////////////////////////////////

        Console.WriteLine("");

        Console.WriteLine("Time difference when DST is on");

        utcDateTime = new DateTime(2018,09,25,09,00,00,DateTimeKind.Utc);       

        Console.WriteLine("Time in UTC: "+utcDateTime.ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Newfoundland

        Console.WriteLine("Time in Newfoundland: "+ConvertToRestaurantTime(utcDateTime, "Newfoundland Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Atlantic 

        Console.WriteLine("Time in Atlantic: "+ConvertToRestaurantTime(utcDateTime, "Atlantic Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Eastern

        Console.WriteLine("Time in Eastern: "+ConvertToRestaurantTime(utcDateTime, "Eastern Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Central

        Console.WriteLine("Time in Central: "+ConvertToRestaurantTime(utcDateTime, "Central Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Moutain

        Console.WriteLine("Time in Mountain: "+ConvertToRestaurantTime(utcDateTime, "Mountain Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Saskatchewan

        Console.WriteLine("Time in Saskatchewan: "+ConvertToRestaurantTime(utcDateTime, "Canada Central Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

        //Time in Pacific

        Console.WriteLine("Time in Pacific: "+ConvertToRestaurantTime(utcDateTime, "Pacific Standard Time").ToString("yyyy-MM-dd hh:mm:ss tt"));

    }

    public static DateTime ConvertToRestaurantTime(DateTime currentTime, string timeZone)

        {

            DateTime changedKind = DateTime.SpecifyKind(currentTime, DateTimeKind.Unspecified);

            TimeZoneInfo restaurantZone = TimeZoneInfo.FindSystemTimeZoneById(timeZone);

            currentTime = TimeZoneInfo.ConvertTime(changedKind, TimeZoneInfo.Local, restaurantZone);

            return currentTime;

        }

}