Hi JP,

You ask,

We tried, with some success.   My mother in law would suddenly try to go to
bed at 3 in the afternoon (when she thought it was night), and imagined it
was "bedtime".    We deliberately kept her from going to bed during daytime
hours, up till about 7 PM, but would let her go to bed after dinner if she
wanted.   At one point we put a lock on her bedroom door from about 3 to 6
PM.    She would go down the hall, try the door and come back to the main
area of the house over and over again.     If she snoozed on the sofa during
the day we didn't bother her about it.

Only a few times she got up and tried to get dressed in the middle of the
night, thinking it was morning.    She would wake up, see that the house was
quiet and would just lay quietly in bed.    We would give her a Tylenol PM
(which contains a little benadryl) and it helped her to sleep through the
night, early in the game when she first came here.   Later on she had no
problems sleeping, so we discontinued it.

Everyone is different, and my mother in law used to snooze on the sofa
during the day if she felt sleepy.   We didn't bother her if she did this,
but we also didn't want her to go into the bedroom and sleep there because
of the mixed up day and night issues.

John, find out what works for you best.   What worked for us may not be the
best thing for you, but then again it may.   We didn't want her roaming
around at night, because we were afraid she would get into something, so
keeping days and nights on track was an issue for us.