Age of purchases

If I buy singles or even Tubos, how would I know how aged they are. I am reading that most Cubans need to be aged, so I have a range of Punch, RyJ and Monte's that I bought in June, how would I find out how old they are /were and do they really need laying down.... same goes for New world as well i guess, but I don't see much about them being a "must" age... thanks all