The time for one hour b4 London open should be (GMT) 7am. As what I've learned from babypips.com, London open is at (GMT)8 a.m. My broker time zone is GMT+3, therefore 08:00 + 3:00 = 11:00, therefore I set the periodBegin=08:00(3 hrs b4 London open), PeriodEnd=11:00. That's what I've learned from Eagle's posts. I might be wrong so correct me.