Now...what I want to know...Is how long spices are good for?

After our dd was born, I found a jar of cinnamon or something similar (nutmeg maybe?) in my ILs pantry dated the year dh was born (Ew!) Which I, of course, tossed. FIL was very miffed at me; I don't easily get on his good side, LOL. I've read since that they are of course most flavorful as soon as they are opening and lose their flavor after a year...but...well, at what point do you not want to ingest them?