you should always trade using multiple time frames . I think the time is right when the current trading session change banks, because the transaction takes place at a time. i think you also should trade in long time frame. i trading in the hour 4 and hour 1 time frame and if you are scalper than you can use the time frame of 15 minutes and 5 minute chart, trade time koi bhi ho ap ko yai matter zaydah nahe karta hai bas ap ko is mai yai janny ki zrurat hoti hai k apna analyse ko better karny ki try kary yahe cheeze he ap ko best mil sakti hai always aur ise k sath he ap market view kar sakty hain aur jis time apka analyse us market par utray then he ap entry lain lain..