1855 followed by 1856
1855 (MDCCCLV) was a common year starting on Monday of the Gregorian calendar and a common year starting on Saturday of the Julian calendar, the 1855th year of the Common Era (CE) and Anno Domini (AD) designations, the 855th  year of the 2nd millennium, the 55th  year of the 19th century, and the  6th   year of the 1850s decade. As of the start of 1855, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923.