I post birthdays if I see them on the bottom of the forums. These show up if people put them in their profiles. If you didn’t add it to your profile here on the forums, it won’t show up. I also post a birthday thread if I see it through Facebook. If I’m not your friend there, I won’t see it there either.
And other people are more than welcome to wish a garrison member a happy birthday if they happen to know when it's somebody’s birthday too.

So in short, I'm sorry if I missed your birthday and that's the reason you may not have received a birthday wish here.