during a period when you were not active or alive.
I don't know how old the bridge is, but I know it was built well before my time.
before time
adverb long ago. Hawaiian youth usage US, 1982
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.
*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.