1771: AM and AG Oct 20, 2019

Yesterday, the Latin precursor for BC, ACN, was discussed, but this is far from the only notation for years out there. In addition to the secular BCE and CE (Before Common Era; Common Era)—replacements to AD and BC/ACN respectively—there is also AM or 'Anno Mundi'. This is not so widely used anymore, but meaning 'in the year of the world', this was used in tandem with AD to refer to modern dates based off of the year of creation as described in Genesis. To be clear, it actually starts just under 1 year before creation, yielding this current year as AM 5780. Other than this, a few minor systems for notation exist, like Anno Graecum (AG), with the years starting with the reconquest of Babylon.