When I was a kid, it'd have to be Memorial Day. All the extended family would convene at the old family cemetery to decorate the graves. That isn't the weird thing... the weird thing was we treated it as a family reunion and picnicked together among the head stones.
I don't know what your families nationality is, but this is very common in some countries (not for memorial day, specifically, but picnicking in the cemetery on a holiday).
What is the weirdest thing that your family does together?
When I was a kid, it'd have to be Memorial Day. All the extended family would convene at the old family cemetery to decorate the graves. That isn't the weird thing... the weird thing was we treated it as a family reunion and picnicked together among the head stones.