Is Friday really your worst trading day? You do not need to guess. Your trade history can tell you.
Group your trades by weekday
Separate your historical trades into Monday through Friday and calculate performance for each group. You might find Monday shows +$1,220 with a 1.31 profit factor while Friday shows -$1,960 with a 0.71 profit factor. If your real trading history looked like this, Friday would deserve investigation.
Do not immediately stop trading your worst day
There may be another explanation. Maybe your strategy encounters different conditions on that day. Maybe a few unusually large losses distorted the result. Maybe you become more aggressive after a losing week. Analysis should lead to questions rather than arbitrary rules.
Combine day and time
Things become even more interesting when you combine dimensions. Maybe Friday is not the problem, maybe Friday afternoon is. Or Tuesday might appear extremely profitable because Tuesday morning contains nearly all the gains. That is the advantage of analyzing raw trade data rather than simply looking at your account balance.
Look at behavior
Are you taking more trades on losing days? Does position size increase later in the week? Do you hold losing trades longer on Fridays? Do you trade differently after a strong Monday? These behavioral patterns are worth investigating.
Your best trading day is personal
There is no universal most profitable day that applies to every trader, market and strategy. Your useful answer is contained in your own trading history. MyTraderScore can help turn that history into performance breakdowns so you can identify patterns worth investigating.