An occurrence with no stated end runs until the next one opens. That is the
boundary a bare rotation was missing — docs/SOURCES.md declines to publish
arustats' Abyss openings precisely because nothing bounded them — and here
it is entailed by the interval the reader typed rather than invented for
them. The store still holds endsAt: null; only this projection resolves it.
nextOccurrences returns what has not finished rather than what is running,
so a rule between cycles answers "opens Saturday" instead of vanishing for
its whole off week.
The "ancient anchor" test's expected occurrences now include 31 August: with
a six-year-old anchor at 09:00 and a query window opening at midnight, that
day's occurrence (no stated end, so it runs until 1 September 09:00 opens
the next) genuinely overlaps the window's first nine hours — the same edge
rule the sibling "overlapping at either edge" test exists to prove. The
brief's original expected list omitted it.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
