First, the prayers and offerings for the dead has nothing to do with their salvation.
Ecclesiastes 9:5 For the living know that they will die; But the dead know nothing, And they have no more reward, For the memory of them is forgotten.
Second, the dead don't have a day and visiting them to show your love and compassion is something the dead will never know.
Ecclesiastes 9:6 Also their love, their hatred, and their envy have now perished; Nevermore will they have a share In anything done under the sun.
Third, the dead shall be judged according to the works done while still living.
Revelation 20:12 And I saw the dead, small and great, standing before God, and books were opened. And another book was opened, which is the Book of Life. And the dead were judged according to their works, by the things which were written in the books.
Knowing that we shall be judged for our own sin, we can do nothing for the salvation of the dead.
Deuteronomy 24:16 “Fathers shall not be put to death for their children, nor shall children be put to death for their fathers; a person shall be put to death for his own sin.
What is All Souls Day then? Perhaps, a picnic, a gatherings or a family get together that can be done with or without the dead under.