Rhonda, you are correct, the time zone does not play into things much anymore. The only effect time zone has on the Prep now is (1) when 10/1 begins, (2) when 10/3 ends (deadline to officially participate), and (3) when 10/31 ends. Generally, since everyone is on the honor system anyway, we err on the side the best case scenario for the participants when we enforce cutoffs. For example, we didn't implement the 10/3 cutoff until 8am on 10/4 WDC time, which is the latest possible time that 10/3 could be ending anywhere in the world.

Cheers,
Michelle