For prisoners time must seem like it's going slow and a minute probably seems like 2 hours and an hour probably seems like 12 hours.
But time never speeds up or slows down and time always goes at the same speed for everyone no matter where they are or what they are doing.
The time seems like it's going by slowly in prison because of the boredom and the the prisoners are waiting until the time in prison is up so they can be released if they have a release date.
I imagine the time in prison for life in prison without parole prisoners goes by slowly at least for the first 10 to 20 years in prison.
Then later they get into a routine and the time just goes by without them thinking about it.
But I would imagine that if I were in prison which I never hope to be that if I was in prison sitting around doing nothing and watching a clock tick by then the time would drag.