---
title: JSON-LD declares dateModified
description: "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."
doc_version: 0.2.0
last_updated: "2026-04-24T21:30:56.217Z"
---

## 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

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

### Fail

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

## Sitemap

Full docs site index: [/sitemap.md](/sitemap.md).