This message is confusing, but what it means is that there may be (probably
is) a difference between the time/date/time zone on your computer and your
Nook. If you haven't set up your Nook yet, this could be the cause. If
you've already gone to the B&N website and registered it, using your Adobe
ID and password, then check your time and date settings on the Nook first,
then on your computer.
Hope this will help!