Hi, I just installed your plug-in and think it looks perfect for my needs on the site I manage (www.ttne.us). I'm having a similar problem as Jason, I've set the site for the New York timezone and entered 18:00 for a 6pm EST ending time on April 17, 2013.
I used the timeduration link Jason posted above and the time that it displayed, isn't matching with the calculation the timer is displaying. The link says that it should be 126 days, 5 hours and 25 minutes as I'm writing this, but the widget is showing 126 days, 9 hours and 5 minutes.
I'm sure that I'm missing something simple, but didn't want to look for another countdown timer as the others really pale in comparison.
Thanks in advance