TO TALK TO YOU'Synchronous communication technologies facilitate coordination, afford social accessibility, and allow for flexible contact at a distance. The authors investigate the temporal structure of social accessibility, individuals' definitions of public and private time, and how social accessibility and privacy are negotiated. They examine university students' social accessibility in instant messaging with a multi-method study utilizing surveys, focus groups and interviews.Four key characteristics were identified: predictability, downtime, online concurrent IM activities, and multitasking. Private and public time blur seamlessly in IM, with students making themselves available as a function of social relationships and context. Negotiation of social accessibility is complex and often evolves over the development of a relationship. Three strategies are discussed that help students manage their availability in IM. Despite the lack of formal rules in the use of these strategies, participants have shared understandings of these practices, and the meaning they convey to others.