JSON-LD declares dateModified

dateModified lets agents tell when content has actually changed, which is what makes incremental re-ingestion possible. Without it, every refresh of an agent's index has to treat the page as new.

page Structured data impl 1.0.0 html.json-ld.date-modified

How the check decides

The check parses every JSON-LD block on the page, walks every node (including arrays and @graph children), and asserts at least one node has a non-empty dateModified field. Returns N/A if no JSON-LD exists. Fails if JSON-LD exists but no node declares dateModified.

How to implement it

Include dateModified in your top-level JSON-LD object, populated from the source file’s last-modified time or your CMS. ISO 8601 format is the safest.

Pass

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "TechArticle",
  "dateModified": "2026-04-01T12:34:56Z"
}
</script>

Fail

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "TechArticle"
}
</script>