I don't even want to know what the oldest item in our fridge is. I try to pretend the stuff in the back doesn't exist.
actually the oldest thing is the wassail i made in 2015. aside from that i think there is some chili from last week, and the rogan josh sauce from a few months ago. ah, no, wrong. the oldest thing is the smoked fish i brought with us when we moved here in march of 2015. it's vacuum packed. unsure how long it was in the fridge in florida - six months to a year, likely.
we don't have anything old in the freezer, and aside from the items above, if it is more than a week old then i throw it out (i know, i know, who are you and what have you done with wolfish?).