Diplomats, officials, scientists and other actors working with the Antarctic Treaty System have not simply negotiated a range of measures for regulating human access to the region in a physical sense. They are also continually negotiating a cultural order, one in which time is central. Antarctic actors are aware that the Treaty did not once exist and may cease to exist sometime in the future. They are conscious of environmental change. Each actor tries to elevate their standing and power in the system by deploying temporal ideas and discourses in their interactions with each other: bringing their histories into negotiations, trying to control the idea of the future. This article will map three temporalities within Treaty history: first, the deployment and potency of histories and futures, their relative rhythms and lengths; second, permanence and expiration, the questions and politics of how long the Treaty should or might last; and third, the periodisation of the Treaty period, both among actors themselves and among scholars studying Antarctica.