Timing the cleanse

If I did not eat or drink anything from 11:45 a.m. on,
would there be any reason to not start the liver cleanse
at 5 p.m. instead of 6? In otherwords, move everything up
by and hour. I am usually in bed by 8:30, staying up until
at least ten would not be preferable. I would still do the
third drink not before 6 a.m.
Thanks.