Modification Date (dateModified)

For articles, news and blog posts, Google recommends the datePublished and dateModified properties in structured dataSchema markup is code that describes a page's content in a structured way, so search engines understand it not just as text but as clearly classified information.Open glossary entry →, each in ISO 8601 format and ideally with a time zone. datePublished stays the original publication date, while dateModified shows the last relevant content revision.

Key principles:

• The visible date on the page should not be contradictory.
• Multiple conflicting dates can confuse.
• The modification datelastmod is an element in the XML sitemap indicating when a URL's main content was last significantly changed. It is only useful when maintained reliably.Open glossary entry → should not be set automatically on every deploy or template change.

As with lastmod in the sitemapAn XML sitemap is a machine-readable file listing a website's important URLs. It helps search engines discover content more efficiently but does not replace internal linking or guarantee indexing.Open glossary entry →, the date should reflect real, significant changes. A new date without a real update is a pseudo-update that can damage credibility.

Where the modification date appears #

The same date should be consistent in three places: the visible "updated" line on the page, the dateModified property in Article schema, and the lastmod value in the XML sitemapExtensible Markup Language (XML) is a flexible text format for storing and exchanging data in a structured way. In the SEO context, the XML sitemap is best known.Open glossary entry →. Search engines cross-check these signals; contradictions make all of them less trustworthy.

Common mistakes #

The classic anti-pattern is bumping the date without changing the content — engines compare the stored copy and learn to ignore your dates. Equally common: a CMSA content management system (CMS) is software for creating, managing and publishing web content, usually without programming knowledge. Well-known examples are WordPress or Shopify.Open glossary entry → that rewrites dateModified on every deploy, so every page claims to be brand new. Update the date only when the substance of the page actually changed.