1687 (MDCLXXXVII) was a common year starting on Wednesday of the Gregorian calendar and a common year starting on Saturday of the Julian calendar, the 1687th year of the Common Era (CE) and Anno Domini (AD) designations, the 687th year of the 2nd millennium, the 87th year of the 17th century, and the 8th year of the 1680s decade. As of the start of 1687, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.