**Main is red on the FNXC gate again** — third occurrence of this class
today, third different file.
```
packages/core/src/task-store/task-update.ts: 2 future-dated FNXC stamp(s), baseline allows 1
```
Stamps dated **2026-08-01** while UTC is **2026-07-31-14:24**. Every
open PR inherits the failure; #3164 merged carrying it.
## The fix
Date only, to today. Clock times preserved exactly — they were real
times on the wrong day — and no comment text touched, so the record
reads identically, just in order:
```
-FNXC:StateMachine 2026-08-01-10:20 (PR #2793's finding — the INNER half, merged with #2821):
+FNXC:StateMachine 2026-07-31-10:20 (PR #2793's finding — the INNER half, merged with #2821):
```
Baseline **tightened** as a side effect (`1 → 0`): one future stamp was
grandfathered, normalizing the file cleared it too, and the gate refuses
a stale allowance on the way down. Re-recorded in the same commit.
## The recurrence is the point, not this fix
Three separate files have tripped this in one day — `scheduler.ts`, the
scheduler PG test, and now `task-update.ts` — plus the midnight-rollover
variant this morning that reddened everyone's baseline.
**Stamps are written from a local clock and validated against UTC.** A
worker behind UTC writes what is genuinely "today" for them and produces
a future stamp the moment UTC has already rolled. Nothing in the local
loop catches it: `pnpm lint` passes locally because the local date
agrees.
The durable fix is to generate the stamp from `date -u` rather than a
wall clock — one line in whatever produces these, and the class
disappears. I have patched the symptom three times today; someone should
take the cause. I have not done it myself because the stamps are
authored by hand across every worker's flow, so the change belongs
wherever that convention is documented, not in a file I happen to be
touching.
## Verification
`check-fnxc-future-dates` green (TZ=UTC CI=true) · `pnpm test:gate` 13 +
161 + 487 + 71 · lint · core typecheck clean · diff is date
substitutions only.
2a57820dd2