I read a thing on when they put a bunch of people in a building with no outside stimuli ,clocks etc ,and people tended to gravitate towards 26 hour long days or cyclesNah man, they did a test where they put a woman into a cave with no natural light so she couldnt tell what time it was so she would only go to sleep when she was tired. She lived in that cave for a year I think. She counted the days by when she woke up and went to sleep. At the end she was staying awake for days and sleeping for days I think.