I am American as well, and I agree you don't see it or pay attention to it often. The problem is non-American's who google search the time to convert it to their timezone will get the wrong time, so they should honor the time they posted. I even pointed out the problem two hours ago and told Swede here:
https://bitcointalk.org/index.php?topic=263445.msg2841157#msg2841157This.
Of course they should honor the time posted, it doesn't really matter if they "thought" they were posted something else, or every contract everywhere would be meaningless...
Also the world doesn't revolve around CENTRAL TIME USA you better give times in UTC when doing IPO.
I shouldn't be quoting myself but I said that on page 18
+1