April 1st as a Pagan Holiday....
Day of Hathor in ancient Egypt.
Hathor: In Egyptian mythology the sky goddess and the daughter of Ra. In legends, Hathor is associated with most of the other goddesses. Hathor was depicted as a cow with a sun disk between her horns or as a slender woman with a headress of horns and sun disk. Ancient Greeks identified Hathor with the goddess Aphrodite.
Pic: http://upload.wikimedia.org/wikipedia/commons/thumb/4/47/Hathor.svg/254px-Hathor.svg.png
Kali's Day in India.
Kali: A Hindu goddess associated with death and destruction. The name Kali means "black", but hasby folk etymology come to mean "force of time (kala)". Despite her negative connotations, she is today considered the goddess of time and change. Although sometimes presented as dark and violent, her earliest incarnation as a figure of annihilation still has some influence. She is also revered as Bhavatarini (literally "redeemer of the universe"). Comparatively recent devotional movements largely conceive Kali as a benevolent mother goddess.
Pic1: http://upload.wikimedia.org/wikipedia/commons/c/c5/Kali_Devi.jpg
Pic2: http://www.exoticindiaart.com/artimages/ba22.jpgBy the way she has ten arms! (it may not be 10 horns)
May 15th as a Pagan Holiday....
Mercuralia is an Ancient Roman celebration known also as the "Festival of Mercury". Mercury was thought to be the god of merchants and commerce. On May 15th merchants would sprinkle their heads, their ships and merchandise, and their businesses with water taken from the well at Port Capena.
Ides of May that the Vestal virgins preformed rites to bless and entice the water for the coming Summer.
Feast of Ochossi, Orisha of Animals (African origin). Involves sacrificing to all the deities annually.
See the book (google) Africanisms in American culture By Joseph E. Holloway
I hop this helps