Sites like http://checkcosmetic.net/ can be of some use.
Not always reliable, though.
there is a way to understand "year of production" of a single bottle of scent? In a general way, looking the cardboard box we can assume that parfume was produced during , for example, 1972-1985, but this is too generic...
Sometimes there is a batch number (or similar sequence of numbers) on the box, but how to use it?
Aside from checkcosmetic, some boxes will list a "best by..." date (which I have yet to see myself). Regardless, if stored properly your fragrance should last much longer than the recommended 3 years.
thank you...and yes, I have a bottle of Eau Sauvage Christian Dior, 20 yrs old, and still perfect!