It really depends on your approach and what you're doing. If you're consistently profitable as a technical trader, have your methodology fully worked out and have answered all the questions that needs to be asked, it's only a matter of executing your strategy/system for as long as you desire or need. If you're sufficiently capitalized, you can do very well just trading the initial 60/90 minutes of the daily market session. You can then choose to quit for the day or you may trade the full session. Some even trade multiple sessions, i.e., USA, Asia and Europe.
However, you will never get to this stage unless you work 24/7 for a long, long time. Or less than 24/7, but for a far longer time. And you may never arrive anyhow. Especially if you don't have a mentor or guidance from someone who knows what they're doing. Most don't get that.
I think the reason many don't get a mentor is because they not ready to get one, "I recall back in 2008 when i first started trading i asked someone who i though to be a trader (not sure if he was or not) but he gave me an answer and said "When the student is ready the teacher will appear" Funny thing fast forward to 2016 when i was still trading but not yet successful and had a job a coworker asked me to teach him how to trade, i chuckled and laughed about it and said to him "When the student is ready the teacher will appear." Today 5 years later he is trading, he knows a lot more than he did before which was nothing, yet he is stuck at one strategy and one style he learned from a class which isn't wrong but he has no idea of the whole picture or other strategies for the sake of knowing them or improving what he already does, for example he knows delta but doesn't know extrinsic. The point is, i would be willing to teach him except that he is stuck doing what he does which will work modestly but after 2 to 4 years in my opinion he will realize its not making the gains he expected and or so much time has passed without progressing. Thus many of those so called "looking for mentors" are stuck in their ways, which only time changes, As Richard Dennis has said that if you get them young enough (fresh mind) you can teach them anything but most people are printer perennial bulls. Thus as one said above if you do it less than 24/7 its gonna take reaaaaaaaaaaaaaly loooong time, i know that was the case at least for me, 10 years of zero success, never even got lucky on that "one trade"