Unicorn
The Unicorn, it turns out, like the Phoenix, the Sphinx, or the Chimaera ("Flying she-goat"), is a composite-beast--a unique, a-zoological animal combining two or three or four or five different animals (each symbolic of a different season) into one that stands for a particular calendar-system. The Babylonian calendar-beast was Lion, Serpent, Eagle and Bull; the Carian's Chimaera was Lion, Goat, Serpent. And so the Unicorn originally was a composite of five beasts - Horse, Deer (or Goat), Lion, Rhinoceros (or Narwhal) and Elephant to represent the two Solstices, two Equinoxes and the First day of the New Year.
Together then symbolized an agricultural calendar-system based on nature's cycles and consisting of thirteen months and one extra day, also therefore explaining the ancient phrase "a year and a day."
The five animals of the Unicorn, which in ancient times was the symbol for this calendar-system, represent the passage of the Sun through its five annual seasons:
1. For the New Year’s Extra Day (Dec 23), the body of a Horse-the animal most sacred to the goddess of childbirth (see Silver Fir/Mistletoe).
2. For Spring(celebrated at Equinox, Mar 21), the feet of an Elephant
as Mother Earth's extraordinary power revives (Furze).
3. For Summer(celebrated at Solstice, Jun 21, Oak), the tail of the Lion the animal most sacred to the goddess of love (see Heather).
4. For Autumn(celebrated at Equinox, Sep 22, Vine), the horn of the
Rhinoceros-for power (see White Poplar)
5. For Winter(celebrated at Solstice, Dec 21 Elder), the head of the Deer, or the goat-once hunted only in this death season (see Yew).
The earliest known Greek mention of the Unicorn is by the fifth-century B.C. historian and doctor, Ctesias, who described its spiral horn as being red, white and black. These colors and animals and plants of these colors combined - are the ones most sacred to the ancient European Great Goddess: white for innocence, red for death, black for wisdom. And five was her sacred number, symbolized by the five-pointed star, emblem of inception, birth, life, death, resurrection (see Willow/Blackthorn, and Hazel/Apple).
From A Year and a Day Calendar & Desk Diary 1996 by Peter Bogdanovich