Birthdayless birthdayparty

Because there was birthday 1 at t=0, and birthday 2 will be at t=n, the in-sin inlaws threw a party on time t=m (0<m<n). Btw, none of the featured people is one of the non-birthday people. Well, actually they didn't have their birthday, so technically... Ow, and that foot is probably from one of the non-birthday birthdaypeople, so..

Hmm.. i'm not making this any easier, am i?