> 1. Very early, arriving in C89 and the first drafts of POSIX, with working implementations back into the mid 80's. I looked it up. In fact it's much earlier

> 1. Very early, arriving in C89 and the first drafts of POSIX, with working implementations back into the mid 80's. I looked it up. In fact it's much earlier than that. The API arrived in time.h via v7 Unix in 1979. And it remains, unchanged, pervasively used, and most importantly still used for new code, four and a half decades later. Rather than "legacy cruft", this constitutes one of the most successful utility APIs in human history.