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).
Yes, I found out from my Filipino friends that picnicking among ones ancestors was a thing. Or at least for their family, it was. I kind of like the idea now as a sentimental activity, but kid me thought it was macabre.