On a 12 hr per day timer my bulb lasted just one month. I am returning it and trying a replacement, but not impressed so far.
OK, It is about one month later and the replacement has just failed too. Same 12 hr per day set up, two bulbs have now failed after 1 month. This bulb is the cheapest option, but from my own experience the reason for that is it being an inferior product. Refunds through Amazon are no particular problem, so if you want free bulbs this is the product for you. If you want reliable light for your animal, pay a little more for a superior product. I will be buying an arcadia bulb, since my experience of them is that they last at least six months.