Thursday, March 20, 2025, marks the Persian New Year, or Nowruz, a holiday that's been celebrated for several millenniums, according to the University of Massachusettes. Nowruz, which means “new day” in Persian, is a 3,000-year-old spring festival that is celebrated by millions around the world, according to media outlet Time.

Festivities are under way for Nowruz, popularly known as the Persian New Year. Believed to have been celebrated for more than 3,000 years, the festival is held on the spring equinox to usher in the blooming season.

More than 300 million people in Iran and beyond celebrate the ancient holiday. It’s tied to the spring equinox and has roots in the Persian Empire. Here’s what to know.