International Relations has an 'orthodox set' of benchmark dates by which much of its research and teaching is organized: 1500, 1648, 1919, 1945 and 1989. This article argues that International Relations scholars need to question the ways in which these orthodox dates serve as internal and external points of reference, think more critically about how benchmark dates are established, and generate a revised set of benchmark dates that better reflects macro-historical international dynamics. The first part of the article questions the appropriateness of the orthodox set of benchmark dates as ways of framing the discipline's self-understanding. The second and third sections look at what counts as a benchmark date, and why. We systematize benchmark dates drawn from mainstream International Relations theories (realism, liberalism, constructivism/English School and sociological approaches) and then aggregate their criteria. The fourth section of the article uses this exercise to construct a revised set of benchmark dates which can widen the discipline's theoretical and historical scope. We outline a way of ranking benchmark dates and suggest a means of assessing recent candidates for benchmark status. Overall, the article delivers two main benefits: first, an improved heuristic by which to think critically about foundational dates in the discipline; and, second, a revised set of benchmark dates which can help shift International Relations' centre of gravity away from dynamics of war and peace, and towards a broader range of macro-historical dynamics.