Working with .Net TimeZone Information and Converting Times

A comprehensive list of .Net TimeZone information used for localising .Net applications in conjunction with the CultureInfo class. Timezones are used to help maintain local time and UTC and for conversion between the two.

DateTime dateNow = DateTime.Now;
Console.WriteLine("The date and time are {0} UTC.", TimeZoneInfo.ConvertTimeToUtc(dateNow));

DateTime easternTime = new DateTime(2007, 01, 02, 12, 16, 00);
string easternZoneId = "Eastern Standard Time";
try
{
   TimeZoneInfo easternZone = TimeZoneInfo.FindSystemTimeZoneById(easternZoneId);
   Console.WriteLine("The date and time are {0} UTC.", 
                     TimeZoneInfo.ConvertTimeToUtc(easternTime, easternZone));
}
catch (TimeZoneNotFoundException)
{
   Console.WriteLine("Unable to find the {0} zone in the registry.", 
                     easternZoneId);
}                           
catch (InvalidTimeZoneException)
{
   Console.WriteLine("Registry data on the {0} zone has been corrupted.", 
                     easternZoneId);
}

DateTime hwTime = new DateTime(2007, 02, 01, 08, 00, 00);
try
{
   TimeZoneInfo hwZone = TimeZoneInfo.FindSystemTimeZoneById("Hawaiian Standard Time");
   Console.WriteLine("{0} {1} is {2} local time.", 
           hwTime, 
           hwZone.IsDaylightSavingTime(hwTime) ? hwZone.DaylightName : hwZone.StandardName, 
           TimeZoneInfo.ConvertTime(hwTime, hwZone, TimeZoneInfo.Local));
}
catch (TimeZoneNotFoundException)
{
   Console.WriteLine("The registry does not define the Hawaiian Standard Time zone.");
}                           
catch (InvalidTimeZoneException)
{
   Console.WriteLine("Registry data on the Hawaiian Standard Time zone has been corrupted.");
}

ReadOnlyCollection<TimeZoneInfo> tz;
tz = TimeZoneInfo.GetSystemTimeZones();
StringBuilder sb = new StringBuilder();

foreach (TimeZoneInfo tzi in tz)
{
    sb.AppendLine(tzi.DisplayName + " " + tzi.BaseUtcOffset + " " + tzi.StandardName + " " + tzi.DaylightName + " " + tzi.SupportsDaylightSavingTime);
}

string codes = sb.ToString();
// do what you want with the output, e.g. save it to a file

private void FillTimeZone(ASPxComboBox ddlTimeZone)
{   
   ddlTimeZone.DataSource = TimeZoneInfo.GetSystemTimeZones();   
   ddlTimeZone.DataBind();  
   ListEditItem oListEditItem=new ListEditItem();   
   oListEditItem.Text=Helper.SELECT;   
   oListEditItem.Value=Helper.SELECT;   
   ddlTimeZone.Items.Add(oListEditItem);   
   ddlTimeZone.SelectedIndex = 0;
}

using System;
using System.Collections.Generic;

namespace MyProject.ViewModels
{
    public class TimeZoneViewModel
    {
        public readonly List<CTimeZone> CTimeZones;

        public TimeZoneViewModel()
        {
            CTimeZones = new List<CTimeZone>();
            foreach (TimeZoneInfo z in TimeZoneInfo.GetSystemTimeZones())
            {
                var tz = new CTimeZone(z.Id, z.DisplayName, z.BaseUtcOffset);
                CTimeZones.Add(tz);
            }
        }

    }

    public class CTimeZone
    {
        public string Id { get; set; }
        public string DisplayName { get; set; }
        public TimeSpan BaseUtcOffset { get; set; }

        public CTimeZone(string id, string displayName, TimeSpan utcOffset)
        {
            Id = id;
            DisplayName = displayName;
            BaseUtcOffset = utcOffset;
        }
    }
}

[HttpGet("Api/TimeZones")]
public JsonResult GetTimeZones()
{
    return Json(new TimeZoneViewModel().CTimeZones);
}

[{
    "id": "Dateline Standard Time",
    "displayName": "(UTC-12:00) International Date Line West",
    "baseUtcOffset": "-12:00:00"
  },
  {
    "id": "UTC-11",
    "displayName": "(UTC-11:00) Coordinated Universal Time-11",
    "baseUtcOffset": "-11:00:00"
  },
  {
    "id": "Aleutian Standard Time",
    "displayName": "(UTC-10:00) Aleutian Islands",
    "baseUtcOffset": "-10:00:00"
  },
  {
    "id": "Hawaiian Standard Time",
    "displayName": "(UTC-10:00) Hawaii",
    "baseUtcOffset": "-10:00:00"
  },...