A 0.71*hour candlestick time frame, and not a second less but up to 2 seconds more per candle depending on that day's ATR. -- Seriously though, context is everything, and the time frame only matters based on what the trader is trying to achieve or the strategy they are employing.
Like any other market, should it not depend on what kind of position holding times you're interested in along with what time of day you'll be concentrating on trading?
Are you saying that on the usually rather flat lunch times for instance you change to a shorter/longer T/F
I like to make the entry on a 15 minute time frame and then exit on the 5 minute if I am trading manually. I see daily has 1/3 rd of the votes. Possibly because they are working and only have evenings to trade ?
Did you change this a few times? "what t/f do you recommend for forex" and "which t/f for scalping forex" very different.
No 1)Are you interested in small quick gains/losses or catching swings of hours days or weeks? 2)Do you plan on trading during relatively low volatility times or during fed announcements etc.? I'm assuming you don't plan on staring at your chart/quotes 24 hours a day. To me the defacto "standard" time frame is daily. Although in FX not all chart sources start their new day at the same time. So even these are not all the same. Again imo, ALL intraday times frames are arbitrary. One simply is not and cannot be "better" than any other. It just depends on 1) and 2) above.