I'm also in the Eastern time zone, and the game told me all along that the drawing would be at 9pm (which it was). My first thought when someone mentioned it telling them a time an hour off was to wonder whether that player's PC/console was set to the wrong timezone, but it seems too many people have had this problem for that to be a likely reason. Surely not many players would have that set wrong.

Could it be a bug in just one platform's software making it adjust timezones incorrectly? I'm on PS4, and it worked right for me. Those of you who saw it an hour off, what platform are you on?

(Oh, and it might be worth also checking your system's timezone settings, just in case.)