How much interval do you leave to close trades before the end of a session? (10min, 15min etc), and is there any strong reason you picked that particular number?
If you want to cut it very close I would recommend you have extended trading hours enabled. I believe this is an extra fee (been a while since I did it) but would be worth it. Personally I use a "LastBar" on a 10 or 15 minute minute chart and don't try to be too cute with the close. Depending on your broker certain trades may not fill automatically - specifically shorts. So if you want to get a manual fill you'll want a couple minutes to call. Just closing positions should never require that, of course. Good luck, Damien