CalDavSynchronizer.Implementation.Events.TimeZoneMapper.WindowsToIana C# (CSharp) Метод

        public static string WindowsToIana(string windowsZoneId)
        {
          if (windowsZoneId.Equals("UTC", StringComparison.Ordinal))
            return "Etc/UTC";

          var tzdbSource = NodaTime.TimeZones.TzdbDateTimeZoneSource.Default;
          TimeZoneInfo tzi;
          try
          {
            tzi = TimeZoneInfo.FindSystemTimeZoneById (windowsZoneId);
          }
          catch (Exception)
          {
            tzi = TimeZoneInfo.Local;
          }
            
          if (tzi == null)
            return null;
          var tzid = tzdbSource.MapTimeZoneId(tzi);
          if (tzid == null)
            return null;
          return tzdbSource.CanonicalIdMap[tzid];
        }
    }