1880 was a leap year starting on Thursday of the Gregorian calendar and a leap year starting on Tuesday of the Julian calendar, the 1880th year of the Common Era and Anno Domini designations, the 880th year of the 2nd millennium, the 80th year of the 19th century, and the 1st year of the 1880s decade. As of the start of 1880, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923.