Market Open and Close hours

I am new to this platform. I am in UK, as per the time zone US market opens at 2:30PM and closes at 9:00PM. But when I fetched historical data of apple, I found it is showing 8:00 AM to 23:55 PM everyday’s data, which is pre market and post market data I think. But can you please tell me know what timing I will follow for market open hours in the historical data.

Thanks in advance.