1670

1670 (MDCLXX) was a common year starting on Wednesday of the Gregorian calendar and a common year starting on Saturday of the Julian calendar, the 1670th year of the Common Era (CE) and Anno Domini (AD) designations, the 670th year of the 2nd millennium, the 70th year of the 17th century, and the 1st year of the 1670s decade. As of the start of 1670, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.