Time is central to HCI. Humans have varying conceptions and experiences of time: linear versus cyclical; discrete versus continuous; personal versus collective. Computational systems also represent time in various ways. And interaction itself plays out over time. Yet HCI has rarely examined time as a concept in its own right. In particular, the ways in which people conceive of and experience time are often at odds with the ways in which interactive systems represent and express temporal factors. In this workshop we aim to make explicit and question the tacit assumptions that underlie the use of time in human computer interaction. The focal themes for this workshop are: (1) examination of people’s conceptions of time vis a vis various topics (e.g. career, fashion, sustainability); (2) exploration of representations of time in systems; (3) the design of time-oriented interactive systems that support long term reflection, action and behavior change (e.g., as it applies to activities and phenomena like careers, fashion, and sustainability).