National Chianti Day is observed worldwide on September 5, celebrating the renowned red wine from the Chianti region in Tuscany, Italy. The holiday was established in 2016 by Santa Margherita USA, a wine import company. Chianti wines have a rich history, with references dating back to the late 14th century, and the region's borders were first defined in 1427. Chianti is primarily made from Sangiovese grapes, which must constitute at least 80% of the blend, and wines from the original Chianti region are labeled as Chianti Classico, identifiable by a black rooster seal. To celebrate, individuals often enjoy a bottle of Chianti with dinner, participate in wine tastings, or host Chianti-themed gatherings. The holiday encourages sharing experiences on social media using the hashtag #NationalChiantiDay.