1647

1647 (MDCXLVII) was a common year starting on Tuesday of the Gregorian calendar and a common year starting on Friday of the Julian calendar, the 1647th year of the Common Era (CE) and Anno Domini (AD) designations, the 647th year of the 2nd millennium, the 47th year of the 17th century, and the 8th year of the 1640s decade. As of the start of 1647, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.