Since Wicca is derived from ancient European agrarian societies, the Sabbats (similar to sabbath) are closely tied to the seasons and the calendar.  Wiccans claim that the Sabbats have been followed for many thousands of years by ancient cultures such as Nordic, Celtic, Greek, etc.  Following is a list of the eight primary Wiccan Sabbats. The dates referenced here are generally accepted by all Wiccans.

Major Sabbats

1. Imbolc, Feb. 2,
   1. Imbolc (imbolg), which means "in milk", is a celebration of fertility and designates the middle of winter.  Milk was traditionally poured out upon the ground as a type of offering.  Associated with this are the colors white, pink, and red, the amethyst, turquoise, dill, Dragon's blood, frankincense, rosemary, and wildflowers.  It is also known as Groundhog's Day, Candlemas, Blessing of the Plow, Disting, Feast of the Virgin,  Festival of Milk,
2. Beltane, April 30 or May 1
   1. Beltane is the first holiday of summer and signifies the approach of summer and the death of winter.  This is an ancient celebration of the return of fertility to the world after it passes through winter.  It divided the Celtic year into winter and summer.  It stresses human fertility.  Associated with this festival is Boodstone, sapphire, frankincense, honeysuckle, Jasmine, St. John's Wort, rosemary, green, yellow, and red. It is also known as Beltaine, May Day, Roodmass, and Walpurgis.
3. Lughnasadh, Aug 1
   1. This festival marks the beginning of the harvest season and the middle of summer.  The word probably derives from the god Lugh, the Celtic lord of light. Associated with Lughnasadh is Crabapple, ginseng, grapes, potato, berries, green, orange, yellow, and red.  It is also known as Ceresalia, First Harvest, Lad Day, and Lammas.
4. Samhain, Oct 31
   1. Samhain means "summer's end" and marks the beginning of winter.  For most Wiccans, this is the new year anytime of reflection where the oldest let go and the new is anticipated.  From ancient times it designates the end of the harvest season.  Associated with the festival are the colors black and orange, obsidian, Onyx, apples, catnip, corn, pears, squash, wormwood.  It is also known as Halloween, All Hallows Eve, Blood feast, Celtic New Year, Day of the Dead, Last Harvest, Winters Eve, etc.

Minor Sabbats

1. Yule, Dec. 21 (Winter Solstice)
   1. This is the winter solstice, the shortest day of the year.  The festival associated with it celebrates the birth of the new solar year.  The solstice is linked to the rebirth and renewal of the sun god, the lord.  Associated with Yule is holly, pine, evergreen, tree (Christmas tree), the gods Odin and Pan, Cedar, cinnamon, ginger, lemon, orange, sage, rosemary, Gold, green, yellow, white, red.  The Yule is also known as Day of Children, Midwinter, Mother's Night, Saturnalia, and Christmas.
2. Ostara (Spring Equinox), Mar 21
   1. The day and night are of equal length. Ostara is name of the Scandinavian Goddess of spring and the festival deals with fertility, mainly of the animal kingdom and plants.  it celebrates the dead of winter and the beginning of the cycle of rebirth.  During this festival that was customary to exchange colored eggs.  Associated with this festival is Moonstone, rose quartz, daffodils, ginger, frankincense, Jasmine, nutmeg, sandalwood, rose, blue, pink, and red.  It is also known as Alban Eilir, Easter, Lady Day, and Waxing Equinox.
3. Midsummer Eve (Summer Solstice), June 21st or 22nd
   1. The longest day of the year and designates a festival of thankfulness.  It celebrates the dissent of the sun because too much sun can harm crops.  Associated with it are the emerald, Jade, Tiger's eye, Apple, Daisy, turn, frankincense, Lily, oak, orange, thyme, green, yellow, and white.  It is also known as Litha, Vestalia, and Whitsuntide.
4. Mabon (Autumn Equinox), Sept 21
   1. The day and night are of equal length.  This is a festival that designates the beginning of fall.  It marks the dissent of the Goddess into the underworld. Associated with it are amethyst, Topaz, acorns, corn, frankincense, great, oak, wheat, brown, and orange.  It is also known as Mabon, Alban Elfer, Harcest, Second, Harvest, and Wine Harvest.