The pattern is predictable even though it moves
Reporting peaks follow the calendar rather than occurring randomly, but they do not fall on the same weekday each month. A schedule written against fixed days will be wrong most months, while one written against the reporting cycle will be right every time. The distinction matters because it changes the arrangement from something managed by exception to something that is simply part of the plan.
Quarter end and year end sit on the same cycle but carry considerably more weight. A schedule that handles an ordinary month end well can still be defeated by a year end where the office is fully occupied for a fortnight of evenings. Naming those heavier periods separately, and stating a different arrangement for them, avoids the annual scramble that most finance functions will recognise.
