GateTrue

What each generator documents about marking its output

Reading date: when the source was last consulted

The reading date on a value marks when its vendor page was last consulted. No other date here speaks to freshness, and this one advances every time somebody confirms the value. As of 2026-09-22.

Which of two dates moves, and whenOne date records when a value is known to hold from, and it moves only when the value itself changes. The other records when the vendor page was last opened, and it moves on every confirmation. Only the second says anything about freshness.Known to hold fromLast read onMoves whenThe value changesAnybody opens the pageAnswersHow long has this been trueHow recently was this checkedOn a confirmationUnchangedMoves to todayTravels withThe recorded fieldThe recorded fieldRead the date next to the evidence class, not on its own
Fig. 1 A single timestamp would make a long-standing value checked yesterday look identical to a value written yesterday.
How this register uses the term, and what it excludes. Written 2026-09-22.
The termReading date
What it namesThe day the vendor page behind a value was read
What it is notThe day the vendor changed anything
Where the register uses itBeside every value, and in the data file

Inclusion rule. Words this site uses in a narrow sense, where the ordinary sense would lead a reader to misread a cell. No vendor statement appears on this page. Order. Fixed order: what the word names, what it excludes, then where it is used here.

1Two dates, doing different jobs

One records when a value was first written down and is expected to hold from; the other records when the page was last opened to confirm it. Only the second moves on a confirmation, which is what makes it the freshness signal.

Separating them lets a reader see a value that has held for months and was checked yesterday, which is a different thing from a value written yesterday. Both facts matter and a single timestamp would collapse them.

2Why it is not a publication date

A page's own lastmod tells a reader when this site changed, which is nearly useless for judging a vendor statement. A reader wants to know when somebody last looked at the source, and that is a per-value fact rather than a per-page one.

So the reading date travels with the field, into the tables, the readings and the exported file. A row quoted somewhere else takes its date with it, which is the only way a quotation stays honest.

3What a stale date means, and what it does not

It means nobody has checked recently, not that the value is wrong. Pricing pages change rarely and unpredictably, so an old date on a stable statement is often perfectly accurate and an old date on a redrawn grid may be badly wrong.

Which is why the date is printed beside the evidence class rather than alone. A sentence read six months ago is a better bet than a layout reading of the same age, and the two dates look identical without the class beside them.

Nothing on this page is a vendor statement; the values it helps read are on the support table, with the page and the date each one was read from. See also the protocol page, what earns a row. Nearby terms: value since, stable identifier, not documented.