1620

1620 (MDCXX) was a leap year starting on Wednesday of the Gregorian calendar and a leap year starting on Saturday of the Julian calendar, the 1620th year of the Common Era (CE) and Anno Domini (AD) designations, the 620th year of the 2nd millennium, the 20th year of the 17th century, and the 1st year of the 1620s decade. As of the start of 1620, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.