re: the pagan calendar of festivals... well, the usual Wheel of the Year most witches follow is based on the old agricultural/seasonal calendar, with the major festivals occurring on the Solstices and Equinoxes, and the Cross Quarter Days in between, thus:

Yule (Dec 22 approx)
Imbolc (Feb 2)
Ostara (March 21 approx)
Beltane (May 1)
Litha (June 21 approx)
Lammas (August 1)
Mabon (Sept. 21 approx)
Samhain (Oct. 31)

The Provider Cycle includes some of the sigificant lunar events (full and new moons) surrounding those festival days to create its own cycle...

peg