Discussions of world history often focus on the pros and cons of thinking on large spatial scales. However, world history also tends to employ unusually large timescales, both for research and teaching; frequently it is framed around a teleology and a series of "revolutions" which mark milestones taking humans from a very distant past to "modernity". Moreover, world history usually rejects regionally specific period markers (e.g. Renaissance), making periodization within this long timespan especially difficult. This article surveys various approaches to these problems, and shows that any of them, if treated as sufficient by itself, introduces significant distortions. It argues for a world history that highlights this problem, rather than hiding it, and which uses the need to deploy multiple timescales simultaneously to clarify the distinctive intellectual contribution of historical thinking.