Prisoners who suffered from "provisional existence of unknown limit" experienced a strange time experience: A day lasted longer than a week.
Book: Man's Search for Meaning
The depressing life in the concentration camp is a "provisional existence of unknown limit", where the prisoners cannot know how long their term of imprisonment would be. With no date given for release, their term was not only uncertain but unlimited.
A person who couldn't see the end of their provisional existence was not able to aim at an ultimate goal in life. They ceased living for the future. They suffered from a strange time experience. In camp, a smaller time unit, like a day, appeared endless since the day was filled with hourly tortures and fatigue. A larger time unit, like a week, seemed to pass faster.
This peculiar sort of deformed inner time turned out to be experienced not just in the camp. Research work done on unemployed miners and tuberculosis patients in a sanatorium also showed that they experienced the same, for they were all without a future a without a goal.