Short answer: half a term to be safe; two to three terms to be good. The foundations — a policy, staff guidance, an initial training session — are achievable inside six weeks with focus. Embedded use, where AI is a normal part of how most staff work and the time savings show up reliably, realistically takes two to three terms.
What the timeline actually looks like
A sensible sequence: weeks 1–3, audit workload and get the policy drafted and approved; weeks 4–6, whole-staff training and one target task embedded; term two, expand to a second and third task with regular check-ins; term three, review against your baseline and make it business as usual. Our step-by-step introduction guide walks the whole sequence.
Why schools stall
Two patterns cause most stalls: trying to change everything at once (nothing embeds), and treating one INSET as the whole programme (enthusiasm fades by half-term). Slow, sequenced, and supported beats fast and abandoned — the schools showing real hours saved a year in are the ones that treated adoption as a rolling process, not an event.