Lol. I never do any celebrating for my bday, haven't really since I was 16. Dinner out with my parents when I lived near them, now, I just buy a slice of cake, lol.
Well there's no harm in asking, you can always preface with I know you're busy with school stuff, so it's no problem if you don't have time! but, would you like to...
hmm, you could go to a movie, our just out for lunch or dinner and hang around chatting, or invite them back to your place and order in a pizza and pop in a movie...?