1656 (MDCLVI) was a leap year starting on Saturday of the Gregorian calendar and a leap year starting on Tuesday of the Julian calendar, the 1656th year of the Common Era (CE) and Anno Domini (AD) designations, the 656th year of the 2nd millennium, the 56th year of the 17th century, and the 7th year of the 1650s decade. As of the start of 1656, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.