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.