Google has made a small note to the sitemap documentation to add that the lastmod date specified in the sitemap file "should reflect the date and time of the last significant update to the page." This change was made after I covered the topic of Google trusting or not trusting that lastmod field in your sitemap file.
Gagan Ghotra spotted this update and posted on X about it. He said, "Google added a note about lastmode in Search Central document about sitemaps." He is right.
When you compare the old version to the current version - you can see this document was updated on June 21, 2024.
Google added this section:
The lastmod value should reflect the date and time of the last significant update to the page. For example, an update to the main content, the structured data, or links on the page is generally considered significant, however an update to the copyright date is not.
Here is a screenshot:
Google also made one small additional tweak to the text sitemap section, just to clarify it. Here is what was added in blue:
Search Central document was updated on 21 June.
— Gagan Ghotra (@gaganghotra_) June 25, 2024
On 11 June @rustybrick reported this https://t.co/MLfx3KYgHL when @methode
on LinkedIn posted that Google "either trust it or not" when it comes to the lastmod date.
This update to document seems like Google providing more context… https://t.co/CHVr5m4VwZ pic.twitter.com/11R2Z13CWi
Forum discussion at X.
