My perspective is the one-minute chart, feeling for the trending day, long or short. And I do find testing over only six months to be reliable. But not three. And I find that optimized profit targets vary over those time scales.
Quote from BrooksRimes:
For an intraday system such as based on 5 minute bars that generates a few trades per day, how far should it be backtested?
This is for futures (ES, NQ, TF, YM ZB).
Brooks