Drink by Dates:  While every effort is made to ensure accuracy, these dates should be used as a guide only.  The evolution of the wine will greatly depend on your storage conditions over time.  It is also important to consider that personal taste also plays a factor.  If you prefer fruitier, more robust wine, then you should drink them sooner.  If left longer the wine will develop a more mature, evolved style. 

Ultimately, the best way to see how the wine is progressing, relative to your taste, is to open one periodically.