Festival of Isis, ancient Egypt

These were Winter Solstice celebrations in which worshippers led the goddess in the form of a golden cow, covered by a black veil, seven times round the shrine of the dead Osiris in the temple of Helios in a perambulation called 'the seeking for Osiris'. This represents the wanderings of Isis who journeyed over the world mourning for his death and searching for the scattered parts of his body.

Legend of Osiris and Isis    Deities of many cultures in the Book of Days

The birth of the divine child, whether he bears the name of Horus, Osiris, Helios, Dionysus or Aeon, was celebrated in the Koreion in Alexandria, in the temple dedicated to Kore, on the day of the winter solstice.
Neumann, Erich, The Great Mother, Princeton Univ Press, 1972, p. 312

More about the birth of ancient gods and saviours at Winter SolsticeTerence McKenna, Mayan calendar and Timewave Zero 2012
If you have come to this page looking for these subjects, they are at December 21 in the Book of Days, and at the Calendar Convergence page in the Scriptorium.