This article resituates the study of time in anthropology, moving it from the comparative exploration of internally coherent religions and national territories to the very margins of religions, nations, and capital. Borders recalibrate time by imbuing mundane economic activities with political salience. Dangerous border crossings make temporal registers contingent and erratic, and generative of violence and torture. I show how India’s prohibitions on live cattle exports and Bangladesh’s demand for beef compel acts that effectively legalize animal smuggling, which, nonetheless, remains a risky business. Across the riverine islands of the India-Bangladesh borderlands, small-scale traders and transporters operate according to the distinct logics of militarized infrastructures and legal regimes that generate moments of “signal clear,” marking the temporary opening of border passages and opportunities for sustenance, as well as “armed” times, more sustained periods of heightened national security, and imminent violence. By subjecting the border’s productive and coercive temporal energies to close ethnographic scrutiny, I suggest that cattle’s sacrality reinforces the material world of capital and strife, ruptures kinship ties, and subjects Muslim cattle workers and their families to prolonged periods of scarcity and hunger. This article shows how people’s experiences of the borderland as a space are vitally shaped by fractured, shifting, and contingent rhythms of time.