Idioms and Phrases with keep late hours
keep late hours
Stay awake until late at night. For example, Never call Ethel before noon; she keeps late hours and sleeps all morning.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.