There are NO dumb questions. There are just questions that I don't know the answers to yet.
My sister has a chicken that is still laying everyday during summer at the age of 10 years. So unless you can't provide for the ducks, keep them as long as they meet your needs. They need a water source like a pond or and swimming pool and food, everything else is a bonus. Light will effect a birds laying cycle. Chickens need at least 14 hours a day. i am not sure what ducks need.
I would think that being a bird it will be close.