The only timezone that kinda works currently is EST, which is at 5:00 PM for them. Most people are off work by that point and can participate. The problem begins once you start including the rest of the country, however. By the time you get to where the server is located, 4:00 PM, you are already starting to run into issues.
As you get into mountain time, and then Pacific, it goes from bad to a complete joke. The NCSoft West HQ is located in California, which is at the 2:00 PM Olympiad time I am speaking about.
Having to be at home in front of your PC by 2:00 PM on a Weekday, means you are ducking out of work at 1:30 PM or even earlier depending on your commute home. This is the middle of the work day.
To call this a complete joke would be an understatement. As others have mentioned, it is a "compromise" for the Brazilians, and mostly for the Europeans. But guess what? The Europeans already have these exact same servers, with all events set around their prime time gaming hours. Meanwhile, our own NA servers, NCSoft West, are totally throwing Americans under the bus for the benefit of the Europeans who already have their own Aden servers.