It will never go "bad" as-in spoil or be harmful. I wouldn't think a canned beer would be an issue for years so long as it wasn't stored too hot.

Some higher alcohol beers are meant to be aged like wine. Hoppy beers lose their hop punch and aroma after a few months. For this reason I always look for dates when buying IPAs, fresher the better, but within 3 months. Any beer that gets oxygen in it will start to taste like cardboard. If it gets an infection it will sour (but still not hurt you to drink it, the same cultures are used to sour beers on purpose).

blatz , falstaff, schlitz, (according to dad)

4 to six months in a 65 degree basement