With the growing complexity of social and environmental issues, there has been a blossoming of hackathons and open innovation challenges. This push to accelerate innovation embraces a perspective of time as clock time—conceived as objective, linear, measurable, and therefore, rather easy to compress. Such a view of time conflicts with the emergent nature of idea generation and the indeterminate process that leads to social impact, which both rely on event time. Drawing on a 40-month ethnographic study of OpenIDEO, an open social innovation platform, I examine how, in designing open innovation challenges, the OpenIDEO team interwove clock time and event time in order to foster idea generation and support social impact. Through inductive analysis, I identify three practices—mapping, stretching, and squeezing time—enacted by the OpenIDEO team to “make time” and thus, continuously engage participants and sponsors in the challenges as well as to allow participants to implement their ideas. My findings demonstrate how organizations can intentionally use time to nurture collaborative innovation and yield sustainable social impact. My study questions the traditional interpretation of clock time as the foundation of all temporalities as it shows how temporal work can be grounded within event time.