Thirteen is certainly the most essentially female number -- the average number of menstrual cycles in a year. The approximate number, too, of annual cycles of the moon. When Chinese women make offerings of moon cakes, there are sure to be 13 on the platter. Thirteen is the number of blood, fertility, and lunar potency. 13 is the lucky number of the Great Goddess.
Representing as it does, the number of revolutions the moon makes around the earth in a year, 13 was the number of regeneration for pre-Columbian Mexicans. In ancient Israel, 13 was a sanctified number. Thirteen items were decreed necessary for the tabernacle. At 13 years of age, a boy was (and still is) initiated into the adult Jewish community. In Wicca, the pagan goddess tradition of Old Europe, communicants convene in covens of 13 participants. Thirteen was also auspicious for the Egyptians, who believed that life has 13 stages, the last of which is death -- the transition to eternal life.
Held holy in honor of Shekinah, the female aspect of God, Friday was observed as the day of Her special celebrations. Jews around the world still begin the observance of the Sabbath at sunset on Friday evenings when they invite in the Sabbath Bride. Friday is the Sabbath in the Islamic world. Friday is sacred to Oshun, the Yoruba orisha of opulent sensuality and overwhelming femininity, and also to Frig, the Norse Goddess of love and sex, of fertility and creativity. Her name became the Anglo-Saxon noun for love, and in the 16th century, frig came to mean "to copulate."
Friday was associated with the early Mother Creation Goddesses for whom that day was named. In Anglo-Saxon, Scandinavian, Icelandic, and Teutonic cultures She was called variously, Freya, Freia, Freyja, Fir, Frea and Frig. Friday is Frig's Day, Frigedaeg, in Old English, Fredag in Danish, Freitag in Dutch. In Mediterranean lands, She reigned as Venus. In Latin, Friday is the Day of Venus, Dies Veneris; Vendredi in French, Venerdi in Italian and Viernes in Spanish.
Friday the 13th is ultimately the celebration of the lives and loves of Lady Luck. On this, Her doubly-dedicated day, let us consider what fortuitous coincidences constitute our fate. The lucky blend of just the right conditions, chemistries, elements, and energies that comprise our universe. The way it all works. The way we are. That we are at all.
As western Judeo-Christian culture was spread through colonisation these older cultures disappeared or went underground.