I always mark the date of installation of any new light bulb on the base somewhere with a Sharpie pen. I thought the curly lights were a good idea, at first. The lifespan seems to be about one third that of a tungsten filament light. The latest I changed out was a (relatively) new three-way that was supposed to last 6 years by GE (made in China). Installed April 1, 2009: died the death September 2, 2010. Alas, I've replaced it with the old filament type. Cheaper, better.