Just received an email about the PI ActiveView webinar and spent 10 minutes trying to figure out what 9am Pacific time would be in my local time (BST). I am somewhat hampered by not knowing whether you mean Pacific Standard Time (PST) or Pacific Daylight-Savings Time (PDT). I have plumped for it being 5pm BST (which is 4pm UTC).
Would it be possible to give the webinar times in UTC as well as Pacific Time. People are far more likely to know what their local time is relative to UTC than they are to know what it is relative to the local time in California.