JP's birthday is 3 months away... Unless you're talking about a different JP than JP? Or this is a REALLY early Happy Birthday... in which case, it's a good way to make sure you're not late!
And the cake you saw everyone eating was brought by Max, and as far as I know was a "why not" cake, not a birthday cake. Although just as delicious. JP's "28th" birthday is not for some time.