What Is dateModified?

How dateModified Works

dateModified is one property in the schema.org vocabulary, the shared set of types and properties search engines use to read structured data. Per its official definition, it applies to a CreativeWork — the parent type of Article, BlogPosting, WebPage, and similar — and expresses “the date on which the CreativeWork was most recently modified.” Its expected value type is Date or DateTime, and in practice it is written in ISO 8601 format, for example 2026-07-15 or 2026-07-15T09:30:00-05:00.

It rarely travels alone. In article structured data, dateModified is paired with datePublished: the published date is fixed at first publication and never changes, while the modified date advances every time the content is substantively updated. Together they let a search engine distinguish a brand-new page from an old page that was recently refreshed — a distinction that feeds directly into content freshness assessment under the query deserves freshness logic.

The property’s practical value is that it gives search engines a clean, machine-readable date rather than forcing them to guess from the page text. But it is an assertion, not evidence. Google’s guidance on dates is explicit that it maintains its own records of when it crawled and indexed content, and weighs the dates you supply against them. dateModified earns its keep only when it tracks a real change; decoupled from actual edits, it becomes the raw material of freshness spoofing.

How to Implement dateModified Correctly

A few rules keep the property honest and useful:

• Match the visible date. Google advises using exactly the same date in structured data as the update date shown in the page’s visible content. A dateModified that disagrees with the on-page date is a signal at war with itself.
• Drive it from real edits. Wire the value to your CMS’s genuine last-modified timestamp so it advances when — and only when — the content changes.
• Use ISO 8601, with a time zone when you can. A full DateTime with an offset removes ambiguity about which day the update landed on.
• Keep datePublished fixed. Don’t overwrite the original publication date on update; that erases a legitimate signal and can look like date manipulation.

Example of dateModified

A minimal, spec-correct example is an Article node in JSON-LD carrying both dates:

{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "Content Refresh: A Practical Guide",
  "datePublished": "2024-02-10T08:00:00-05:00",
  "dateModified": "2026-07-15T09:30:00-05:00"
}

This says the article first published in February 2024 and was last substantively updated on July 15, 2026. The values follow the schema.org contract — dateModified is a DateTime on a CreativeWork — and Google can use them to display the update date in search results and to inform its freshness reading.

The correctness of the example, though, lives outside the markup. For the dateModified above to be legitimate, the page must actually have been meaningfully edited on that date, and the same “Updated July 15, 2026” should appear in the visible content, exactly as Google’s date guidance recommends. If the body still reflects the 2024 version, the JSON-LD is syntactically perfect and substantively false — and Google, comparing it against its crawl history, can simply disregard it. The example that matters is not the code; it is the code matched to a real change.

dateModified in the Freshness Workflow

dateModified is the reporting layer of a larger cycle. When a page decays and you run a content refresh, updating the property is the final honest step — recording that the change happened so search engines can factor it in. Handled that way, it is a faithful ledger of your maintenance. The failure mode is treating it as a dial to turn independently of the content, which is precisely the line between a real update and freshness spoofing. The property is trivial to write; its entire worth rests on whether the change it claims is true.

Frequently Asked Questions

The Bottom Line

dateModified is the structured-data field that tells search engines when a page’s content last meaningfully changed. Paired with datePublished, it lets Google surface an accurate update date and factor freshness into ranking — but only as a claim it cross-checks against its own crawl records. Kept in sync with the visible on-page date and driven by real edits, it is a small, honest signal; detached from actual changes, it is worth nothing.