night owl
nighthawk
nightbird

Then I started working days, and she has become a night owl.

If you are a night owl this really is the place to come to.

Also like the main character, he is a night owl.

You either have to be an early bird or a night owl, she told herself.

Charlie lived alone and she knew him to be a night owl.

She knew he was a night owl and preferred this time to do his writing.

But not too late for a night owl like Cindy.

People who have this problem may be called "night owls."

I think the night owl in me is trying to get out.

A small number of routes run 24 hours a day in "night owl" service.