(not going back to bed), could this be a beginning sign of dementia? This elderly person used to go to bed still early (about 7:00 PM until about 5:00 AM), but, as I said earlier, now it has shifted to waking up for the day at around 1:00 AM. Is this cause for concern and what could be causing this change?
You might try to change their internal clock by adjusting the bedtime a little later and later in increments. It may take months, but if it works, that would be great.
Just curious, who cooks for this elderly person? If the person doesn't do the cooking, then who ever does needs to bump the supper time to a later hour, such as 6 pm.