Juice shelf life is merely suggestive, much like expiration dates on food. The only purpose is to cover the manufacturer's proverbial butt. Expiration dates have very little to do with reality. I have some yogurt in my fridge that is over 2 weeks past its expiration, but it still tastes just fine.
I know this is a older thread but I thought I would share this info. I have had juice that is three years old taste as good as when I bought them. I have found that the lighter colored juices hold up longer, IMO. I also found that some of the food, bakery, candy type juices seem to change flavor quite a bit with age.I keep my juice in the basement which keeps a temperature about the same year around, about 66 to 70 degrees. I keep my juice on a shelf away from sun light. Some suppliers will give you a lower shelf life because perhaps the ingrediants will go bad faster. I am a tobacco type guy. Aroma's Sahara and as of late Ry4 flavors are my favorites. 555 is also in there. I don't care to much for the food/ sweets type juice. I like to eat my food and desert. That's just my taste. The juice I did open at around it's third birthday was a tobacco flavor and tasted very good. It boils down to each individual flavor might have a different shelf life. Always try them out before tossing them. I actually had a few taste better after a year and got a reprieve from the garbage can. Sorry if a couple words are spelled wrong, my spell check doesn't come up here.