School life in England (and beyond) is temporally structured, with learning planned as a time-limited activity, both within lessons and across units of work. Discourses of performativity and measurement pervade school life in many societies and, what we call "regulated time" controls school-based learning. In particular, primary mathematics learning is often marked by a focus on speed and pace and on children and teachers demonstrating progress against fragmented goals. Taking this as an exemplar, and in the context of the pedagogical approaches promoted through two curriculum development projects, we consider disruptions to regulated approaches to learning as children and teachers work collaboratively on mathematical activities. We argue that the "expansive" timescape that emerges is generated through extended timescales and through an acceptance of unfinishedness, a key change from usual school mathematics that leaves mathematical meaning making open to revision, providing a more meaning-full experience of primary mathematics.