As many manufacturers on amazon or google or any other marketplace describe in the listing that their light bulbs can work continuously for 30000 hours or 10 years,consumers would always doubt about these figures,in fact, some merchants will actually fake the product life and wattage.
So,how long do dusk to dawn lights last?It depends:
Dusk to dawn light bulbs of which brands?
Like some well-known brands, the life of the product will have credibility, such as Philips,as Philips promise ‘Each bulb is expected to deliver a lifetime of up to 22,000 hours (based on three hours per day), saving you the cost and hassle of frequent bulb replacement.’,so 22,000 hours would be the ture lifetime of a Philips dusk to dawn light bulbs,some others like Lohasled dusk to dawn light bulbs can also work for 5 years according to amazon reviews,the worst ones which sold on ebay without brands would have no quality assurance at all.
Where to use Dusk to dawn light bulbs?
Compared to traditional LED bulbs, dusk to dawn bulbs are special in that they are equipped with a photocell sensor that can automatically turn on and off when it detects daylight.The same product of the same brand, the length of continuous lighting time determines the actual life of the bulbs.So if you put it in a totally dark room,it would be turned on and lighting up all the time,but if install it in a garden where would be bright to dark as the sun rise and set,the bulbs would light up for only 12 hrs at most and even only 5-6 hrs in winter or some special temperature zone.
Of course the enviroment temperature also influnence the lifetime dusk to dawn light bulb,too cold or too hot would cause parts to malfunction.