The Stoics had a calendar problem nobody talks about. Seneca noticed that people budget money with meticulous care — tracking expenditures, auditing losses — yet surrender hours to visitors, obligations, and small disruptions without a second thought. His word for this was *iactura*: wastage, the kind that happens not through one catastrophic decision but through a thousand tiny defaults. What makes this more than ancient scolding is what modern research on self-interruption clarifies. Gloria Mark at UC Irvine found that people interrupt their own work — not external distractions, themselves — roughly every three and a half minutes. Seneca's insight and Mark's data converge on the same uncomfortable point: the primary thief of your time is not circumstances or other people. It is the low-level permission you continuously grant yourself to scatter. The practical consequence is narrow and specific: the unit of time worth protecting is not the day or the hour but the unbroken stretch — and most of us have quietly stopped believing we're entitled to one.

When did you last protect an unbroken stretch of time from yourself — not from others, but from your own impulse to break it?

Drawing from Stoicism combined with cognitive psychology of attention — Seneca ('Epistulae Morales ad Lucilium', c. 65 CE) and Gloria Mark ('Attention Span', 2023)