I decided to make my own holiday inspired by
Dia de los Muertos (Day of the Dead) and the fact that our first city parks were once cemeteries and that people would go for picnics there. Except this holiday is a bit more party. Thus the name which translates to Party with the Deceased though according to a South American friend of mine (who is upset that Jungle Adventures was mostly Central American culture) told me that Fellecidos could also mean "dead" much like Muertos. It's just a more professional way of saying that word.
The traditions for this holiday would be remembrance, grand meal, and party spirit. It is customary that you dine in a mausoleum or cemetery as the grand feast is supposed to be held alongside the deceased person's grave or urn.