System.TimeZoneInfo.FromRegistryKey C# (CSharp) Method

		private static TimeZoneInfo FromRegistryKey (string id, RegistryKey key)
		{
			byte [] reg_tzi = (byte []) key.GetValue ("TZI");

			if (reg_tzi == null)
				throw new InvalidTimeZoneException ();

			int bias = BitConverter.ToInt32 (reg_tzi, 0);
			TimeSpan baseUtcOffset = new TimeSpan (0, -bias, 0);

			string display_name = (string) key.GetValue ("Display");
			string standard_name = (string) key.GetValue ("Std");
			string daylight_name = (string) key.GetValue ("Dlt");

			List<AdjustmentRule> adjustmentRules = new List<AdjustmentRule> ();

			RegistryKey dst_key = key.OpenSubKey ("Dynamic DST", false);
			if (dst_key != null) {
				int first_year = (int) dst_key.GetValue ("FirstEntry");
				int last_year = (int) dst_key.GetValue ("LastEntry");
				int year;

				for (year=first_year; year<=last_year; year++) {
					byte [] dst_tzi = (byte []) dst_key.GetValue (year.ToString ());
					if (dst_tzi != null) {
						int start_year = year == first_year ? 1 : year;
						int end_year = year == last_year ? 9999 : year;
						ParseRegTzi(adjustmentRules, start_year, end_year, dst_tzi);
					}
				}
			}
			else
				ParseRegTzi(adjustmentRules, 1, 9999, reg_tzi);

			return CreateCustomTimeZone (id, baseUtcOffset, display_name, standard_name, daylight_name, ValidateRules (adjustmentRules).ToArray ());
		}