You might find this article interesting from The Balance.com, but every one is different. Go with what suits your personality type:
(Below are just partial quotes. Click link for entire article)
Best Times of the Day to Buy and Sell Stocks
Here's when it might be best to trade the stock market
The best times to day trade the stock market may be the first two hours of the day. In the U.S., this is from the time the market opens at 9:30 a.m. ET to 10:30 or 11:30 a.m. ET. Another good time to day trade may be the last hour of the day. In the U.S., that is from 3:00 to 4:00 p.m. ET.
Trading When the Market Opens
Trading during the first one to two hours the stock market is open on any day is all many traders need. The first hour tends to be the most volatile, providing the most opportunity (and potentially the most risk). Although it sounds harsh, professional traders often know that a lot of "dumb money" is flowing at this time.
Futures trade virtually 24 hours per day during the weekday, so if you're day trading index futures such as the E-mini S&P 500 (ES) or an index-based ETF like the SPDR S&P 500 (SPY), you might begin trading as early as 8:00 a.m. during pre-market hours and begin tapering off at around 10:30 a.m. That provides a solid two hours of trading, usually with a lot of profit potential.
Trading During the Last Hour
Many day traders also trade the last hour of the day, from 3:00 to 4:00 p.m. ET. By that time, traders have had a long break since the morning session, allowing them to regroup and regain their focus.
Edited by Rogerdodger, 24 February 2021 - 11:35 AM.