As a North American layman, i never see CDT or EDT used. The most common use of time zones I see is on TV when shows are promoted for their starting time, and it's always EST/CST (I think at least..)
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#msg2841157Unfortunately there is/was little I can/could do about the issue as Burnside runs the exchange and I only am the communications person between Labcoin and BTCT.CO