In Ancient Egypt, the calendar had twelve months which each had thirty days in it. This all added up to a total of 360 days, so the Egyptians added five more days which were not parent of previous or coming months, but were used for festivals. The events that led to the creatzion of these five days began when Ra, the creator of the universe, created Nut, the beautiful goddesses of the sky. He had planned for her to be his wife, but he did not know that she was in love with the earth god Geb. Out of rage, he cursed Nut: “You will not have children during any month of any year.”
Devastated, she called for Thoth’s aid, the God of wisdom, writing, and science. She pleaded for his help, and Thoth felt sorry for her. He hatched a plan to gamble with the moon. He managed to get the seventy second part of the day, and since he was a lunar god, he could take pieces from the moon. Doing this, it began to flicker and weaken. Out of all 
the pieces he got from the moon, he put together five days which were not part of the previous or upcoming year. This gave Nut the opertunity to have five children with her lover Geb. On the first day, Osiris was born. A loud call echoed through the entire world, saying: “The lord of all the earth is born.” He became the first king of the earth, and showed how to properly treat Gods and to be civil with eachother. On the second day, Horus was born. On the third day, Seth was born. He killed Osiris in order to get the throne. On the fourth day, the loving Isis was born, and on the fifth, Nephsis.