Dates agents can read: dateModified, lastmod and freshness

Undated means unknown, not timeless

Many questions have a time component: current prices, this year's rules, the latest version. An engine deciding which of two sources to trust for such a question will take the one whose age it can establish. A page with no date is not treated as evergreen; it is treated as unverifiable, and it falls behind a dated page that says the same thing.

The date printed in your byline helps a person. Machines read structured fields: datePublished and dateModified in JSON-LD, article:modified_time in Open Graph, <lastmod> in the sitemap, and Last-Modified in the HTTP response. The more of these agree, the more confidently the page can be dated.

What Qomvia checks

Content carries a date in the methodology is worth 4 points. It looks for datePublished or dateModified on any JSON-LD node of a content page, and for a <lastmod> on at least one entry of your sitemap. Both present: pass. Structured data only: 3, because discovery has no date. Sitemap only: 2, because the page itself cannot be dated. Neither: fail.

Putting the date where machines look

{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "Swiss VAT rates from 2026",
  "datePublished": "2026-01-08",
  "dateModified": "2026-07-29",
  "author": { "@type": "Organization", "name": "Brand" },
  "publisher": { "@type": "Organization", "name": "Brand" }
}

<url>
  <loc>https://www.brand.ch/guides/swiss-vat-2026</loc>
  <lastmod>2026-07-29</lastmod>
</url>

• Use ISO 8601 (2026-07-29 or 2026-07-29T09:00:00+02:00). Localised formats are ambiguous to a parser.
• dateModified must mean it. A lastmod that updates on every deploy teaches crawlers to ignore it; Google says it uses lastmod when it is consistently accurate, and drops it when it is not.
• Products and organisations can carry dates too: dateModified on a Product, or on the WebPage node, is enough for the check and for a reader.
• Keep the visible date and the structured date in sync. A byline that says 2023 next to a dateModified of yesterday reads as manipulation.

Dates are not for titles

It is tempting to put 'Updated August 2026' in the title so readers see it in results. Do not. The title is a stable label; a date in it goes stale in the index, has to be rewritten every month, and adds nothing a dateModified does not already tell the machine. Qomvia removed dates and scores from its own page titles for that reason, as the metadata article explains.

Questions

Should dateModified change when I fix a typo?

Only if the change matters to a reader. Treat it as 'the content is different now', not 'the file was saved'. Trivial bumps make the field worthless to crawlers.

Does a static marketing page need a date?

Yes, a dateModified on the WebPage node. Prices, addresses and product lists on such pages change, and an engine answering 'what does X cost' wants to know how old the page is.

Is lastmod in the sitemap enough on its own?

It helps discovery and scores partial, but the page itself is still undated when fetched directly, which is how user-triggered agents arrive.