Man can we be a little nicer here. He said "no gain time for time spent in jail" I am not familiar with the term "gain time" but as he uses it above seems to me additional time taken off of your sentence for playing nice. Working dancing to entertain the warden etc.

I took that to mean that while you are in jail you burn down one to one days which is not as fast as the bonus or "gain time" you would get in actual prison.

He may or may not be correct and my guess is it depends on where you at since state and local laws will be applied but... As for knowing what he is talking about my guess is many prisoners are experts in the system of trying to reduce their stays in prison.