1597 (MDXCVII) was a common year starting on Wednesday of the Gregorian calendar and a common year starting on Saturday of the Julian calendar, the 1597th year of the Common Era (CE) and Anno Domini (AD) designations, the 597th year of the 2nd millennium, the 97th year of the 16th century, and the 8th year of the 1590s decade. As of the start of 1597, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.