5th September is the Ancient Egyptian Ceremony of the Raising of the Djed Pillar. The worship of the Djed pillar, and the annual 'Raising of the Djed' ceremony, is amongst the earliest ritualistic religious practices of ancient Egypt.

The Djed was stated to have arisen from the primordial mound of creation and believed to be the backbone of the Egyptian God Wzr (also known as Asar or Osirus) though sometimes associated with the earlier Deity Ptah

In the Osiris myth

Osiris was killed by Set by being tricked into a coffin made to fit Osiris exactly. Set then had the coffin with the now deceased Osiris flung into the Nile. The coffin was carried by the Nile to the ocean and on to the city of Byblos in Lebanon. It ran aground and a sacred tree took root and rapidly grew around the coffin, enclosing the coffin within its trunk. The king of the land, intrigued by the tree's quick growth, ordered the tree cut down and installed as a pillar in his palace, unaware that the tree contained Osiris's body. Meanwhile, Isis searched for Osiris aided by Anubis, and came to know of Osiris's location in Byblos. Isis maneuvered herself into the favor of the king and queen and was granted a boon. She asked for the pillar in the palace hall, and upon being granted it, extracted the coffin from the pillar. She then consecrated the pillar, anointing it with myrrh and wrapping it in linen. This pillar came to be known as the pillar of djed. - Wikipedia