Sites such as yahoo show historical data for stocks. They show stocks for all different stock markets. When they show information for a day for example the hong kong stock market, are those dates shown at local Hong Kong time? SO for example if I see two stocks on Jan 10th, one is a stock trading on the Hong Kong stock market, and the other is trading on the NYSE, is the Jan 10th of the Hong Kong stock actually a few hours ago before (If I was in living in NY) or is it based on a universal timezone like greentime?