time is up

The period of time allowed for something is ended, as in Turn in your papers, students; time is up. This idiom uses up in the sense of “completed” or “expired,” a usage dating from about 1400.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.