Website offering a countdown for desktop that can be customized.?

Someone mentioned a website out there that allows people to put a countdown (I guess it would be like a clock) on their desktop. This countdown can be anything, such as a birthday and lets the user know how many more days/hours etc. to go. I thought the website was countdown.com, but apparently not. Does anyone know what the website (or any other website like it) is? Thank you.