a period of intense pressure; a critical situation: It's crunch time for high-tech companies.Compare crunch(def 10).
Origin of crunch time
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
A period when pressure to succeed is great, often toward the end of an undertaking. For example, It's crunch time—we only have two more days to finish. This term employs crunch in the sense of “a critical situation or test.” [Slang; 1970s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.