Sym454 -9000 -8000 -7000 -6000 -5000 -4000 -3000 -2000 -1000 0 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1710 1720 1730 1740 1750 1760 1770 1780 1790 1800 1810 1820 1830 1840 1850 1860 1870 1880 1890 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1940 1950 1960 1970 1980 1990 2000 2010 2020 2024 2030 2100 2200 2300 2400 2500 2600 3000 January February March April May June July August September October November December -- starts at 1918-12-30