The following are holidays celebrated by Wiccans and pagans in the United States:
Ostara, March 21: Spring Equinox or fertility festival.
Beltane, May 1: Also known as May Day, it celebrates the height of spring. Practices include the dance of the Maypole.
Midsummer, June 21: Also known as Summer Solstice, fire is usually worshiped.
Lughnassad, Aug. 1: First harvest of the year. "Prosperity magic" may be performed and agricultural festivals may be held.
Mabon, Sept. 21: Autumnal equinox and second of the harvest festivals. Wiccans celebrate the past and present, as well as the future.
Samhain, Oct. 31: New Year and most significant Wiccan holiday. Witches honor the dead, make goals for change.
Yule, Dec. 21: Fire festival of the Norse and Winter Solstice.
-- Source: Rocking the Goddess: Campus Wicca for the Student Practitioner