Back in my working days, I once had an appointment with the FAA at 2:30 PM on a Friday.
I got there at 2:00 PM. The office appeared deserted (this was downtown DC in one of those giant office buildings.)
I called out, and a lone voice called out from a distance, “Back here.”
“Where is everyone,” I asked.
“It’s Friday, and everyone likes to get an early start on the weekend.”
It was 1995.
The Feds are free to leave early because they have an army of private contractors doing most of the real work.