A simple option to check the days, and the time range.
Indeed, looking at my best strategies, most profit comes from 'favourable gaps' on positions held over the weekend. It appears, looking through results (45 million generations so far) that genetic has a tendency to hone in on this, and random, if left long enough, will naturally bubble the same to the top of the results pile.
Exit at end of range or Friday, etc. works in a realistic way - which means that if you set the end time too late and the trading will finish before that,
the trades are not closed, and they will be closed on the next tick on the next trading day.