T.N.
That's generally the way a government shut down works. Full time employees can either take leave or they don't get paid for the days the government is shut down. Contractors don't get paid. When the government opens back up, sometimes they pay employees for the days off, sometimes they don't. It depends on what's in the Congressional bill to fund government operations (and that hasn't been voted on yet, so no one knows).
But don't freak out... practically every year there's a threat of a government shutdown, and the last time we had one was YEARS ago.