Now that Google is encouraging publishers to use proper lastmod dates in their sitemap files, what happens if your lastmod date is incorrect and shows the wrong date. Gary Illyes from Google said either Google trusts your lastmod date or doesn’t, there is no in between.
As a reminder, Google (and Bing) recommended sites upgrade to WordPress 6.5 in order to get the automatic lastmod date in your XML sitemap. Gary also added that despite Google ignorning the lastmod date previously, he added, “surprisingly things may change given enough time,” meaning, this is no longer the case.
Gary Illyes said on LinkedIn yesterday that Google “either trust it or not” when it comes to the lastmod date.
Mark Williams-Cook asked Gary:
I guess Google is making its own judgments about how often to crawl without xml sitemap. If I’m specifying lastmod and Google’s signals consistently find I haven’t made significant changes, do you have any kind of reputation system to decide “how much” to trust what a site tells you, or is it just taken as a weighted signal? Please, Gary, I need to know the answer to this for my family Xmas quiz this year. TIA.
Gary Illyes responded:
it’s binary, or at least was last time I checked. we either trust it or not.
Mark had an interesting observation based on the Google search API leak:
Maybe “not new” but I found this interesting:
– Google appears to store “last significant update” time/date in epoch format for URLs
– You can supply lastmod in XML sitemap
– Google has boolean on whether to trust you or not based on whether you’re a naughty liar pic.twitter.com/im6LSykcW0
— Mark Williams-Cook (@thetafferboy) June 11, 2024
Forumd discussion at LinkedIn.