O S T A R A (around March 21st but date may vary by more than two days ) also known as: Spring Equinox, Ostara, Alban Eiler, Esther, Eostre, Ostarun, Östartag', Eastre, Eoastrae, Oestre The first true day of Springtide. The days and nights are now equal in length as the Young God continues to mature and grow. We begin to see shoots of new growth and swelling buds on the trees. Energy is building as the days become warmer with promise.
Pagans call it Ostara , Christians changed it to Easter
"Because the Equinox and Easter are so close, many Catholics and others who celebrate Easter often see this holiday (which observes Christ's resurrection from the dead after his death on Good Friday) as being synonymous with rebirth and rejuvenation: the symbolic resurrection of Christ is echoed in the awakening of the plant and animal life around us. But if we look more closely at some of these Easter customs, we will see that the origins are surprisingly, well, pagan! Eggs, bunnies, candy, Easter baskets, new clothes, all these "traditions" have their origin in practices which may have little or nothing to do with the Christian holiday."
"You Call It Easter, We Call It Ostara" http://www.witchvox.com/holidays/ostara/ostarahistory.html
OSTARA (pronounced O-STAR-ah) is one of the Lesser Wiccan Sabbats, and is usually celebrated on the Vernal or Spring Equinox right around March 21 (although because of its origins, may instead be celebrated on the fixed date of March 25). Other names by which this Sabbat may be known are Oestara, Eostre's Day, Rite of Eostre, Alban Eilir, Festival of the Trees, and Lady Day. The Christian holiday of Easter is very near this same time, (notice the similarity in name?), and is determined as the first Sunday after the first Full Moon after the Vernal Equinox.
The name for this Sabbat actually comes from that of the Teutonic lunar Goddess, Eostre. Her chief symbols were the bunny (for fertility and because the Ancient Ones who worshipped her often saw the image of a rabbit in the full moon), and the egg (representing the cosmic egg of creation). This is where the customs of "Easter Eggs" and the "Easter Bunny" originated.
Ostara is a time to celebrate the arrival of Spring, the renewal and rebirth of Nature herself, and the coming lushness of Summer. It is at this time when light and darkness are in balance, yet the light is growing stronger by the day. The forces of masculine and feminine energy, yin and yang, are also in balance at this time.