1843 followed by 1844
1843 (MDCCCXLIII) was a common year starting on Sunday of the Gregorian calendar and a common year starting on Friday of the Julian calendar, the 1843rd year of the Common Era (CE) and Anno Domini (AD) designations, the 843rd  year of the 2nd millennium, the 43rd  year of the 19th century, and the  4th   year of the 1840s decade. As of the start of 1843, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923.