WHEN IS THE BEST TIME TO TRADE?

I am not exactly sure if there is a best day of the week to trade. In my opinion the Monday and Friday are the days at least trade on. Maybe it is just me but those are the days that I have the least amount of luck. I know a lot of investors prefer to place their trades at the beginning the end of the week. This is because they have an exact idea of how last week's candle close or a good idea of how the current weeks candle will close. Similarly many investors place their bets at the beginning and the end of the day for the same reasoning but instead for daily candles. As for the best day of the week to trade, I do not know. But there are several important times during the day or the month or even the year that investor should pay close attention to. Let's go over them.

For the longer term investor and a day trader there are some very important days of the year many investors should watch. these days are associated with witching days or important days for options expirations. A lot of asset allocation reshuffling takes place within the big investment banks and hedge funds on these days theoretically. The reshuffling might not occur exactly on these days. But usually it happens within a very close time frame of these days. The first day of the year, the first day of the quarter, the first day of the second half. You would definitely want to pay attention to the major options expiration dates that happen near these days that I just mentioned. For instance the options expirations date for the middle of the month and the end of the month can sometimes cause big moves in the market. Also the options expirations for the end of a quarter or the end of the first half of the year are very important as well. I should also mention that the 52-week bottom in the S&P 500 occurred within just a few days of the quad witching day which was the first day of the second half of the year. I don't believe this is a coincidence.
For a short-term trader like a day trader or a swing trader there are also important times of the day that you should pay special attention to. Occasionally these times of the day it will get an influx in volume and/or volatility. I remember when I was a new trader I would always wonder why at certain times of the day you would get spikes and volume or the big moves in price action and whatnot. This could possibly explain some of those times when you might feel the same way.

All the hours I'm using are from Central US time zone, where I am located. You may need to adjust the hours for your time zone possibly.

3:00 a.m. - US pre market opens. This is also when the major European markets of Germany and the United Kingdom open. These two major European markets have the most impact on US equities. Also take note that several stock trading platforms allow pre-market trading at different times. For example Robinhood allows pre-market trading as early as 6:00 a.m. This could possibly be the reason why you can see spikes and pre-market on the low price Meme stocks at this time.
8:00 a.m. - Regular cash trading starts for cash accounts on most exchanges that do not use margin or leverage.
8:30 a.m. - Markets open for regular trading hours. The first 15 to 30 minutes can often be very volatile. So definitely be careful during that time.
12:00 p.m. to 12:30 p.m. - The major European markets of the United Kingdom and Germany come to a close. There are several other smaller European markets with different hours but they have much less of an effect on US equities.
Lunch Time on Wall Street - Very often during US trading hours when it is lunch time in New York there is very low volume traded on the US markets. Those wolves of Wall Street have to eat too you know.
3:00 p.m. - US market close. Sometimes during the last hour you can get some big moves in price. Also I've noticed on some days there is an increased chance for a big move the closer and closer you get to market close.
5:00 p.m. - Futures markets open. Futures markets close at 4:00 p.m. and reopen at 5 p.m. I'm assuming they do this to balance the books or something. But occasionally you can see some small moves when the Futures markets open.

Those are pretty much the only times of the day that affect the US equity markets. But there are other times of the day to pay attention to if you are a cryptocurrency trader.

For example when the equity markets, commodity markets, or the crypto exchange markets open and close in other countries overseas you will often see volume and/or volatility associated with these times of day when you're watching cryptocurrency names.