I use my judgement, since 'dates' only came onboard 20 or so years ago, I learned well from my mother and grands how to tell if something was bad. As for now, it's a way of scaring people to BUY things they don't need. It's like buying new irons every few years because they are spitting. One person told me, but it says NOT to use distilled water in them. Of course it does, that way you have to buy a new one, frequently. My Proctor Silex is 50 years old, just an old cheapie, it's never had a drop of water in it that wasn't distilled. Nary a spit ever. I use it nearly every day as I sew frequently. I love that iron and my pantry.