Several people have reported that their computer’s time is off.
We looked into the issue, and found that our time server had lost some time overnight. It has been fixed, and we’re diagnosing it now.
In the meantime, if your computer’s time is off, please manually reset it using the following link as a reference (time.gov): http://time.gov/timezone.cgi?Eastern/d/-5
On windows, this is done either by right-clicking on the system clock and choosing, “Adjust DateTime”, or by running the command “net time /set” into the Start -> Run dialog box.