Every day since Bing wished me a happy birthday on the 16th, which was my birthday, it has wished me a happy birthday. Ten days later, and Bing still thinks it's my birthday. There is a box that I can click if it isn't my birthday. It brings me to my Microsoft account where I am asked to verify my information, including my birthdate of August 16, 1951. Still, the next day, it thinks it's my birthday. I am thinking they don't have that birthday thing down pat yet.
I have been using Bing rewards for years. While you will never make much, it is a pretty easy way to earn a little.