Why not just remove any ambiguity and post something like:
Buy at 670 on 8/3/2016 12:00:00
instead of forcing people to look up what you mean by open/close. Just common sense.
Seriously? Do you want me to wipe your chin with a nappy and put you to bed afterwards too?
Sheesh! If you can't buy at the OPEN, sell at the CLOSE (about the 5th time I've had to say this . . .) then please do something else with your money other than trading. If those instructions are too hard then trading is just not for you.