Mom is 94 with dementia and does not sleep at night. Any suggestions?

During the day she takes little cat naps. She has this obsession with going to the bathroom every five minutes to do nothing, so her cat naps aren't very long. When you tell her that she just went to the bathroom, she gets very agitated and aggressive. She is taking 1.5 mg of Haldol twice a day to keep her aggressiveness down. Is there a sleep aid that can be given to her to make her sleep at night?