Seems to imply a different amount of time. Work year would be the amount of time worked in a year (usually ~2000 hours give or take). Sort of like how a work-day is 8 hours rather than 24.

Man/woman/person/dev/etc-year seem to imply an amount of work that is equivalent to a year (~8760 hours).

Or at least that's how I would use those terms. It's entirely possible that these definitions are regional in nature.

We were once negotiating an SLA and my colleague happily agreed to a 24 hour turnaround time. I asked him if he thought that was perhaps a bit optimistic and he replied, “24 business hours, that’s a three day turnaround time!”

I always interpret a work year to be the same thing as a person year, which is ~2000 hours.

That is a life-year.