A day to honor the dead is widely recognized as universal, with every continent having its own version.
While All Soul's Day originates in the Christian countries, manifesting itself in Mexico as a day for people to clear the headstones and bring flowers to the graveyards of their ancestors, the Chinese celebrate a similar rite to honor all departed souls, called The Feast of the Hungry Ghosts. And Hindu tradition prescribes that on the first day of the new autumn moon, the head of the family performs ceremonies for the dead of the last three generations. Here in America, we at least recognize those who died in battle on Memorial Day and Veteran's Day.
It's probably a good thing, too, as one dictionary of folklore says, "It is proper to note that the souls of persons who died by violence are more restless and dangerous to the living than the souls of those who died 'naturally'."