Ostara is a pagan festival observed worldwide, celebrated on March 20, marking the spring equinox. This festival symbolizes the arrival of spring and the awakening of nature, associated with the ancient Germanic divinity Ostara, or Ēostre, who represents the goddess of the dawn. The tradition of celebrating the spring equinox emerged after the Germanic tribes conquered Britain in the 5th-6th centuries, with the name Ostara first mentioned by German philologist Jakob Grimm in the 1840s. Ostara is one of the two days of the year when day and night durations are equal, after which days become longer and nights shorter. Many cultures view this equinox as a time for nature's rebirth or the return of fertility gods. The Christian holiday Easter also derives its name from Ostara, reflecting its historical significance.