I prefer during the day, because when you do something at around afternoon hours you are getting a risk, you are betting that when everyone comes from their work you are going to see a rise in the trade. Of course, this is for my own countries national exchange, it is purely fiat to crypto and doesn't really work out on places like binance where you can trade hundreds of coins and everyone around the world can also use which would result with all kinds of time zones.

Since, I do this on my own national currency it is much easier, I just buy at around afternoon and when people comeback home they either buy as well which will make me profit or they will sell which will make me lose. It is a bet you have to really care about and know for sure or at least hope it would. I do not think it has any backing, I just made this up but it has worked more than not.