before time

before (one's) time

Predating one's tenure or when one was born. A: "Have you ever seen this show?" B: "No, sorry, it's before my time." I don't know how that project was organized—it was before my time.
See also: before, time
Farlex Dictionary of Idioms.

*before someone's time

happening before someone was born or old enough to know what was going on. (*Typically: be ~; happen ~; occur ~.) Of course I don't remember it. It was before my time. All that happened before your time.
See also: before, time
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • before (one's) time
  • be before (one's) time
  • be before somebody's time
  • be in (one's) good graces
  • be in somebody's good graces
  • be in someone's good graces
  • go down as (something)
  • at the end of (one's) fingertips
  • at (one's) doorstep
  • at doorstep