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

        public static string IanaToWindows(string ianaZoneId)
        {
            var utcZones = new[] { "Etc/UTC", "Etc/UCT", "Etc/GMT" };
            if (utcZones.Contains(ianaZoneId, StringComparer.Ordinal))
                return "UTC";

            var tzdbSource = NodaTime.TimeZones.TzdbDateTimeZoneSource.Default;

            // resolve any link, since the CLDR doesn't necessarily use canonical IDs
            var links = tzdbSource.CanonicalIdMap
                .Where(x => x.Value.Equals(ianaZoneId, StringComparison.Ordinal))
                .Select(x => x.Key);

            // resolve canonical zones, and include original zone as well
            var possibleZones = tzdbSource.CanonicalIdMap.ContainsKey(ianaZoneId)
                ? links.Concat(new[] { tzdbSource.CanonicalIdMap[ianaZoneId], ianaZoneId })
                : links;

            // map the windows zone
            var mappings = tzdbSource.WindowsMapping.MapZones;
            var item = mappings.FirstOrDefault(x => x.TzdbIds.Any(possibleZones.Contains));
            if (item == null)
                return null;
            return item.WindowsId;
        }