A compact hut magnifies group changes. One person dropping out can create a narrow opening, while a whole-party change can return a rare date at once. HutAlert reports the count it observes rather than assuming which kind occurred.
Common group-planning changes include a traveler dropping out, dates moving, transport no longer working, or the group deciding that current trip conditions do not fit. The public calendar does not identify a cause, and HutAlert never invents one. The only actionable fact is that a positive count appeared after the night had been unavailable.