Sorry, but I presume , that FX market open at 12am GMT Monday (at midnight opens Australia and New Zealand, 1 hour ago (1am GMT) opens Japan etc.) so in the event that you say wait for initial 18 hour price station, it signifies 12am GMT 18hours = 6pm GMT on Monday. If your period is GMT 11 - it means that you need to wait to thuesday - 6pm GMT = 6pm 11 hours following your regional time... 5am Thuesday...
The quote sign, which you posted before are from about 10am Monday GMT I think... - 3 hours following EUR zone opens (two hours following UK opens). Why not... - this might be a good price channel too, but this isn't 18hours from FM market opens...
First of all, we must corretly defined rules - especialy price high and low - greater denoted to GMT time - as opposed to we might have greater outcome together.
PaJaSoft
PS: I think, Oanda allows trade during whole weekend, but this is simply through their coping, not on ECN/ECB... (see liquidity:--RRB-)