Temporality and in particular principals' time use is attracting increasing scholarly attention in educational administration and leadership research. There is a long history of studies looking at how principals spend or allocate their time. This paper draws on initial data from the Principals' Experiencing Time (PET) project which focuses on how principals experience their day rather than conceiving of time as an external resource that is spent (wisely) or wasted. Theoretically informed by Eacott's relational approach and working with data generated through document analysis, interviews, and web-based diary entries, it is argued that the principalship has a temporal foundation. This foundation is constitutive of and emergent from how principals experience their day. Understanding these experiences provides a sound empirical basis for preparation and development programs aimed at current and aspiring school leaders.