Denver Celebrates 303 Day Honoring the Iconic Area Code
Every year on March 3, Denver residents come together to celebrate 303 Day, a tribute to the city’s original area code and everything that makes the Mile High City unique. While the 303 area code has been in use since January 1, 1947, the idea of dedicating a day to it only began in 2009. Though not an official state or city holiday, 303 Day has quickly become a beloved tradition across the Denver metro area and Front Range, much like Colorado Day in August. The date, stylized as 3/03, serves as a perfect reminder for locals to celebrate Denver’s culture, music, food, and outdoor lifestyle.
One of the most enthusiastic 303 Day supporters is Boulder-born electronic duo 3OH!3, whose name itself is a nod to the famous Denver area code. The band has long embraced the tradition, frequently shouting out the holiday on social media, and this year, they’re marking the occasion with a special performance at Larimer Lounge in the RiNo district. The event is expected to draw fans from across the state, adding a musical highlight to the day’s celebrations.
Beyond the concert, locals find their own ways to honor Denver on 303 Day. Whether it’s enjoying live music, exploring one of the city’s many parks, visiting a local brewery, or supporting Denver-based businesses, the day is about celebrating everything that makes the city special. While government offices remain open, the energy in Denver on March 3 feels festive, as residents embrace their local pride and recognize the history and culture of the 303.
