1808 (MDCCCVIII) was a leap year starting on Friday of the Gregorian calendar and a leap year starting on Wednesday of the Julian calendar, the 1808th year of the Common Era (CE) and Anno Domini (AD) designations, the 808th year of the 2nd millennium, the 8th year of the 19th century, and the 9th year of the 1800s decade. As of the start of 1808, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923.