How long do bicycle lights last?

My brand new clip-on battery-operated bike light died after just one hour. How long are they supposed to last?? Is it dead forever? Can I return it?

Battery lights should last a lot longer than 1 hour - duration depending on brand & whether the beam is set on steady or blinking.
For instance, I use a planet bike beamer 5 LED light which aparently can last up to 100 hours in flashing mode before needing to change the batteries

Check out the batteries first. Put some fresh one's in & see how they go. I'm partial to using rechargable batteries, as they can be topped off on a regular basis.

If it's not the batteries fault, than return the light.

I'm sure they're meant to last more than an hour.. faulty ones perhaps? try and return it if it does the same with new battery's (since your battery's might have just been dead already, happens sometimes)