1915 (MCMXV) was a common year starting on Friday of the Gregorian calendar and a common year starting on Thursday of the Julian calendar, the 1915th year of the Common Era (CE) and Anno Domini (AD) designations, the 915th year of the 2nd millennium, the 15th year of the 20th century, and the 6th year of the 1910s decade. As of the start of 1915, the Gregorian calendar was 13 days ahead of the Julian calendar, which remained in localized use until 1923.