how to get TimeZoneInfo short name

Question

Is there any method to get the 3 char code from System.TimeZoneInfo.Local ?

e.g. EDT instead of Eastern Daylight time etc.

Solution 1

Unfortunately, there is no easy built-in way of doing this that I know of. However, you could put something together yourself. Here's an example:

public static class TimeZoneInfoExtensions {

        public static string Abbreviation(this TimeZoneInfo Source) {

        var Map = new Dictionary<string, string>()
        {
            {"eastern standard time","est"},
            {"mountain standard time","mst"},
            {"central standard time","cst"},
            {"pacific standard time","pst"}
            //etc...
        };

        return Map[Source.Id.ToLower()].ToUpper();

    }

}

Use as follows:

string CurrentTimeZoneAbbreviation = System.TimeZoneInfo.Local.Abbreviation();

If you need more conversions you could just plug them into the Map dictionary.

TimeZoneInfo.Id will be a string matching a given key in [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones]. If you can find a matching database online, containing the same Ids as well as the abbreviations, it would be possible to quickly extract and import the pairs (with regular expressions, for example) and drop those into the Map dictionary.

Solution 2

You can write something like:

var abbr = System.TimeZoneInfo.Local.TimeZoneAbbr();

And the helper for it:

public static class ConvertionHelper
{
    public static String TimeZoneAbbr(this TimeZoneInfo zone)
    {
        var zoneName = zone.Id;/* zone.IsDaylightSavingTime(DateTime.UtcNow)
            ? zone.DaylightName
            : zone.StandardName;*/
        var zoneAbbr = zoneName.CapitalLetters();
        return zoneAbbr;
    }

    public static String CapitalLetters(this String str)
    {
        return str.Transform(c => Char.IsUpper(c)
            ? c.ToString(CultureInfo.InvariantCulture)
            : null);
    }

    private static String Transform(this String src, Func<Char, String> transformation)
    {
        if (String.IsNullOrWhiteSpace(src))
        {
            return src;
        }

        var result = src.Select(transformation)
            .Where(res => res != null)
            .ToList();

        return String.Join("", result);
    }
}

Comments

[Feidex]

The possible values for Id can be found in the registry under HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Time Zone (they're different from the names in timeanddate.com/library/abbreviations/timezones )