16-01

1601 (MDCI) was a common year starting on Monday of the Gregorian calendar and a common year starting on Thursday of the Julian calendar, the 1601st year of the Common Era (CE) and Anno Domini (AD) designations, the 601st year of the 2nd millennium, the 1st year of the 17th century, and the 2nd year of the 1600s decade. As of the start of 1601, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.