Doctor Who spans a lot of years (with gaps) which means it's ideal for this type of thing where you type in your date of birth and it finds the episode that aired closest to your birthday. This serves no purpose what so ever except to amuse.
In my case, unfortunately, it was The Time Monster Part 2. I've actually not watched that particular Doctor Who story yet, but partly that's because no one has anything good to say about it.
So what is your Doctor Who birthday episode?