I think we can start trading when the session enters the london session and the price fluctuation is more active in that session after that we keep following the trend to the next session that is new york session and if we samrt we can get pips to earn money in most active sessions. and I prefer the H1 time frame for day trading. Because it gives a very good signal and has a low noise. The smaller time frame mostly gives the wrong signal and brings us to a loss. Trading in H1 is much better than other time period.