I am not up to date on this, but I know that research into
biorhythms has proven conclusively that sleep cycles are
in reply to Re: (OT)Sleeping Patterns
in thread Sleeping Patterns
As you say, minor variations are not a problem for most
people. (There was a case in Israel where a young man
simply could not deviate, causing him enormous trouble in
doing things like attending classes.) In fact very few
people have exactly a 24 hour cycle, so you are "varying"
from your ideal every day. Morning people have something
under 24 hours (they get up earlier and earlier until they
have a reason to stay up) while night-owls have a cycle
over 24 hours (stay up later and later until they have a
reason to get up).
The average is about 25 hours, and one of the best reset
triggers is light.
The people most affected by this are those who do shift
work. In studies (first carried out IIRC in the 70's)
companies that adopted shift work cycles of 3 weeks,
each week moving you to a later shift, had significant
increases in productivity, reductions in accidents, and
improvements in worker morale. Traditional shift work
schedules give just as much opportunities for sleep, but
they don't give opportunities that fit in the biological
clock so well.
FWIW I followed this schedule for about 2 months once
while I was working very hard on something and had no
external scheduling restraints. It worked very well