1773 (MDCCLXXIII) was a common year starting on Friday of the Gregorian calendar and a common year starting on Tuesday of the Julian calendar, the 1773rd year of the Common Era (CE) and Anno Domini (AD) designations, the 773rd year of the 2nd millennium, the 73rd year of the 18th century, and the 4th year of the 1770s decade. As of the start of 1773, the Gregorian calendar was 11 days ahead of the Julian calendar, which remained in localized use until 1923.