I was reading the label on some lightbulbs. It said, "Guaranteed to work up to five years."
Think about that for a minute.
"Up to five years," means any length of time up to five years. If the bulb lasts four years, that's up to five. If the bulb lasts two days, that's up to five.
If I say I'm going to take a nap and I want to sleep up to five hours, that means I don't want to sleep past five hours. So a bulb that will work up to five years means that it won't work a day past five years, and satisfies the guarantee if it burns out before then.
Either the writer is an idiot, or he/she thinks we are idiots.