Knowing what actually accumulated
A reduced attendance is not a suspended one, so the question is what was dropped rather than what was left undone entirely. Usually it is the detail work, periodic items falling due during the period, low-traffic areas and anything requiring equipment that was not deployed. Those are identifiable from the records if somebody kept them, which is exactly why the reduced period should be recorded as it happens. Recording it as it happens costs a minute a night and saves a guess later.
Without that record the recovery is guesswork, and guesswork tends towards the visible. A building recovering on the basis of an inspection will address the areas that look worst, which are not necessarily the ones where something important was missed. A carpet cycle that lapsed and a high-level dust cycle that was skipped will not show up in a walk-through. Those are exactly the items that cost more the longer they wait.
