Why does bottled water have an expiration date?

Every single bottle of water sold in the United States carries an expiration date, despite the fact that water doesn’t go bad. Ever wonder why? New Jersey:

A 1987 NJ state law required all food products sold there to display an expiration date of two years or less from the date of manufacture. Labeling, separating and shipping batches of expiration-dated water to the Garden State seemed a little inefficient to bottled water producers, so most of them simply started giving every bottle a two-year expiration date, no matter where it was going.

The Food and Drug Administration has never set a standard for the life of a bottle of water, and the original New Jersey law has since been repealed. But the expiration date is now industry standard.