code: public static TimeZone getStockTimeZone(String symbol) {
          // First check if it's a known stock index
          if(INDEX_TIMEZONES.containsKey(symbol)) {
              return INDEX_TIMEZONES.get(symbol);
          }
          
          if(!symbol.contains(".")) {
              return ExchangeTimeZone.get("");
          }
          String[] split = symbol.split("\\.");
          return ExchangeTimeZone.get(split[split.length - 1]);
      }
docs: Get the time zone for a specific stock or index.
  For stocks, the exchange suffix is extracted from the stock symbol to retrieve the time zone.
  
  @param symbol stock symbol in YahooFinance
  @return time zone of the exchange on which this stock is traded