The summaries slice and the comprehensive aggregator took their JS windows
(the DAY-bucket bounds, the rollup slope anchors, lastSeen staleness) from
the process clock and their SQL windows (avg7, avg30, the month before, the
median, the 90-day canonical pick, the cold-path slope evidence) from
NOW(), the database's clock. One response mixed two clocks, so a reading
on a window's edge fell in or out with whichever host answered, and with
the process clock pinned the analytics parity walk changed its avg7 with
the hour it ran at.
Each read now takes one `now` and binds it into its statements
(`request-clock-sql.ts`): `$N::timestamp`, which keeps the driver's
offset-free UTC string as written in any session zone. The canonical-pick
helper takes its window as an instant plus an interval instead of reading
NOW(); the series and calendar readers anchor it on their own `since`, the
BP-in-target read on its 365-day start. The window-mean and live-slope
columns the two aggregates each spelled out now come from one builder.
The streak's local day series read its bounds through `::timestamptz`,
which follows the session zone: outside a UTC session today's reading fell
out of the streak. It reads them as UTC first.
The parity walks for analytics, the dashboard summary and the
comprehensive overview pin a fixed day instead of today: their records are
laid out from the anchor day, so the chronotype's work and free nights and
the weight-by-weekday points moved with the weekday the walk ran on. The
snapshots are unchanged. A new suite pins the clock to four times of day,
far from the database clock, with readings ten minutes either side of
every edge, on both read paths, in a UTC and an Auckland session.
A least-squares slope per day over readings minutes apart explodes: three
blood-pressure readings in one sitting, the only ones of the week, fitted
thousands of mmHg per day, and the dashboard tile printed seven days of it
as the 7-day trend. The 30-day fallback had the same flaw.
A window now earns a slope only when its readings fall on at least three
UTC days whose first and last lie at least half the window apart (4 days
for the 7-day window, 15 for the 30-day one). The rule lives once in
window-confidence.ts and gates every path that publishes a windowed trend:
trendSlope (summarize and its callers), the rollup composition and the
live REGR_SLOPE fallback of the summaries slice and the comprehensive
aggregator, and the per-bucket slope of folded week, month and year
buckets. Slope, direction and confidence are present or absent together.
The fit itself stays over individual readings, as the window means do.
The parity snapshots change only where the fixture falls short of the
rule: a weekly body-fat series has two days in its 7-day window, and a
ten-day oxygen-saturation series spans nine days of its 30-day window.
Marc-André Bombeck