Ostara is one of the four lesser Wiccan holidays or sabbats of the Wheel of the Year. Ostara is celebrated on the vernal equinox, in the Northern hemisphere around March 21 and in the Southern hemisphere around September 23, depending upon the specific timing of the equinox. Among the Wiccan sabbats, it is preceded by Imbolc and followed by Beltane.
In the book Eight Sabbats for Witches by Janet and Stewart Farrar, the festival Ostara is characterized by the rejoining of the Mother Goddess and her lover-consort-son, who spent the winter months in death. Other variations include the young God regaining strength in his youth after being born at Yule, and the Goddess returning to her Maiden aspect.
Ostara is the virgin Goddess of spring. This holiday concerns the deity's trip to the underworld, and their struggle to return from the Land of the Dead to Earth. When they accomplish this return, they have a life renewed.
The Church, trying to keep their holidays close to the Pagan holidays, assigned Easter to this time of the year. Like Easter, Ostara is a time to wear your new clothes. It was considered bad luck to wear anything new before Ostara, so the people would work through the winter in secret to make elegant clothes for the Sabbat celebration. The entire community would gather for games, feasting, and religious rituals while showing off their clothing.
The lamb was another symbol of Ostara, and was sacred to the Virgin Goddess of Europe, the Middle East, and North Africa. This symbol was so ingrained in the mindset of the people that it carried over to Passover and Easter.
The modern belief that eggs are delivered by a rabbit known as the Easter Bunny comes from the legend of the Goddess Eostre. So much did a lowly rabbit want to please the Goddess that he laid the sacred eggs in her honour, gaily decorated them, and humbly presented them to her. So pleased was she that she wished all humankind to share in her joy. In honour of her wishes, the rabbit went through the entire world and distributed these little decorated gifts of life.