Story
What changed and why it matters
Darkness can be a unit of time
The striking feature is that the absent Moon still counts. The dark nights after the old Moon disappeared could be numbered and used to coordinate what came next. Timekeeping did not require a clock face to be exact enough for shared plans.
A countdown people can see
A civil calendar hides lunar darkness inside numbered dates. A lunar countdown makes the sky itself the reminder: the old Moon is gone, the dark interval is passing, and the next phase is approaching.
Use the public account conservatively
The source gives a concise example, not a complete Tarkiner calendar. CalculationTime can explain the timekeeping idea while sending readers back to public education and Tasmanian Aboriginal cultural sources for deeper context.