As large-scale climate interventions such as solar geoengineering gain traction in formal assessment processes, the role of computer-based models in shaping anticipatory governance remains underexplored. This paper examines how model intercomparison projects serve as infrastructural sites for synchronization, aligning diverse scientific, technical, and political timelines to facilitate expert foresight. Through an analysis of the Geoengineering Model Intercomparison Project, we demonstrate how the organization of data through experimental protocols and historical simulations is a contested practice where experts negotiate shared schedules and rhythms of anticipation. Our findings reveal that many practices for synchronization are mundane and happen outside formal models. Despite the highly technical nature of computer-based modelling, with its emphasis on the uniform temporality of numerical calculation, we argue that important to the synchronization of deployment scenarios is the exercise of practical judgement, as experts discern and seize opportunities to reorient collective expectations about the future. By foregrounding this kairological dimension to knowledge infrastructures, we highlight the politics of anticipation that experts are engaged in, influencing how societies perceive and respond to the feasibility of large-scale climate interventions.