Ostara is one of the eight major 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.
"The Festival of Ostara at the spring equinox marks the end of winter and the beginning of the season of rebirth (spring), and is celebrated by a blot in honor of Frigg and Freya and/or the disir, the collective of female fertility deities." The "blot" is a celebratory meal (also known as "cakes and ale") that is believed to be shared with the the God/ess.
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.
Wiccan use the term "Cakes and Ale" rather than blots, which is what Heathens and other Norse or Anglo Saxon religions do.