the clock is ticking (down)
US /ðə klɑk ɪz ˈtɪkɪŋ (daʊn)/
UK /ðə klɑk ɪz ˈtɪkɪŋ (daʊn)/
1.
time is running out; there is not much time left to do something
:
•
We need to make a decision quickly, the clock is ticking.
•
With only an hour left before the deadline, the clock was ticking down for the students.