1616 (MDCXVI) was a leap year starting on Friday of the Gregorian calendar and a leap year starting on Monday of the Julian calendar, the 1616th year of the Common Era (CE) and Anno Domini (AD) designations, the 616th year of the 2nd millennium, the 16th year of the 17th century, and the 7th year of the 1610s decade. As of the start of 1616, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.