Definition
If something is described as being 'before someone's time,' it means that it occurred or existed before that person was born or was old enough to remember it.
（某事物）在某人出生或记事之前
I don't really know much about vinyl records; they were before my time.
我不太了解黑胶唱片；它们在我出生之前就存在了。
My memory of that old theater is hazy; it was before my time.
我对那家老剧院的记忆很模糊；它在我记事之前就存在了。
I've never heard of that band; it seems they broke up before my time.
我从未听说过那个乐团；他们似乎在我出生之前就解散了。