I've never heard the term flat time but there is a term called dead time. That is where someone is sitting in jail but not getting credit for it for some reason or the other. It is rare but it can happen. It usually happens in cases when someone is on parole and gets arrested on a new charge. The time they spend in jail will not count towards their new case so it is known as dead time.
Answered on Nov 08th, 2013 at 5:56 PM