1802 (MDCCCII) was a common year starting on Friday of the Gregorian calendar and a common year starting on Wednesday of the Julian calendar, the 1802nd year of the Common Era (CE) and Anno Domini (AD) designations, the 802nd year of the 2nd millennium, the 2nd year of the 19th century, and the 3rd year of the 1800s decade. As of the start of 1802, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923.