If it’s 9:00 at night and your mom wants you to do the dishes, you could try to put it off until the next day by politely pointing out that you are a diurnal animal. That means you get most of your activities done during the day.
The adjective diurnal can be used to describe anything that takes place in the daytime, but it is most often used in the field of biology to describe animals that are active during the day and then sleep at night. Animals with the opposite schedule are said to be nocturnal, which means they’re active at night and sleep in the daytime. Diurnal can also be used to describe something that has a daily cycle, such as a diurnal tide that occurs once each day.