The hard-coded "2026-05-14T13:00:00.000Z" reading was due to fall out
of the snapshot's 14-day `recent` window two weeks after the suite
landed, deterministically breaking the assertion. Anchor the instant
to "today minus 2 days at 13:00 UTC" so it always sits inside the
window, then derive the expected Auckland / Berlin day-keys from
that instant. Keeps the test asserting the same tz-divergence
invariant without baking a calendar date into the suite.