Nut-Cutting Time Meaning

(idiomatic) Time to exert maximum effort, for example, due to an approaching deadline or a looming competitive situation.

Example: Time to gather nuts before they are taken by other animals or buried in snow.
1951, Journal of the Tennessee Academy of Science, vol. 26-27, page 20
  The desire to follow traditions of hunting squirrel in Tennessee during mulberry season in June, and nut-cutting time in September, when squirrels concentrate, [...].