i had meant "we don't have clock fixed to 24 hour day"... and you are correct... but i think we have a
distributed clock mechanism, not one single component called "clock", that is i think related to aging and food intake, because people also do night-shifts at their employment places ( like call centers and factories ) and i have gone without sleep for three days a few times when i was writing my operating system in 2002.
yes, those two idioms apply to much of the world, but the north polar regions have a different environment... from (
There will be darkness: Polar nights in Murmansk | Russia Beyond The Headlines ), i quote...
the polar-night month was feature in the film "30 days of night", if you remember.
strange lands, the north polar region... their days without normal sun... sometimes total dark and sometimes lighting like evenings...