Sym454 -9000 -8000 -7000 -6000 -5000 -4000 -3000 -2000 -1000 0 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1640 1650 1660 1670 1680 1690 1700 1710 1720 1730 1740 1750 1760 1770 1780 1790 1800 1810 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 2000 2024 2100 2200 2300 2400 2500 3000 January February March April May June July August September October November December -- starts at 1841-01-04