Every Historical and Advisory answer stated a window in AEST and queried one
shifted by ten hours.
rolling_window() builds its boundary strings in SITE_TIMEZONE - that is the
whole point of it, and its docstring says so. metrics.run() then posted the
query to Cube with no timezone at all, and Cube defaults to UTC. So
"2026-08-14T15:22:13" meant 15:22 Sydney to the code that produced it and 15:22
UTC to the engine that ran it, and MetricResult.time_window reported
SITE_TIMEZONE from config rather than whatever the query actually used, so the
two could not disagree visibly.
Measured on the fixtures, same dateRange, one field changed:
timezone UTC 8019 samples
timezone Australia/Sydney 8619 samples
600 samples. One per minute, ten hours, exactly the offset.
Nothing about the answer looked wrong. The prose was right, the count was a
real count, the window description was correctly formatted and correctly named
AEST. It was only visible by reading the Cube query in the UI's "show working"
panel - which is an argument for that panel existing, and an argument for
looking at the thing in a browser rather than trusting curl against the API.
- check_cube_query() now takes site_timezone and pins it onto the query, at
the single point every Cube query passes through. Per-query-builder is the
wrong place: "remember to set the timezone" is not a control, and this
defect is what forgetting looks like. An explicit timezone already on the
query is left alone.
- time_window now reports capped["timezone"] - the timezone the query ran in,
not the one it should have run in.
An unpinned timezone belongs in the same guardrail as an unpinned date range,
and for the same reason: both make an answer unreproducible. The difference is
that an unpinned date range is obvious in the query and an unpinned timezone
is invisible.
eval case H28 records it. Two unit tests: the timezone is pinned, and an
explicit one is not overridden.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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