Yeah, they don't seem to make any guarantees at all about the date being displayed next to the search result... I'm too lazy to check the page source here right now on which meta fields are updated with comments, but this is what Google says about how they determine the date:
> Google determines a date using a variety of factors, including but not limited to: any prominent date listed on the page itself or dates provided by the publisher through structured markup.
> Google doesn't depend on one single factor because all of them can be prone to issues. Publishers may not always provide a clear visible date. Sometimes, structured data may be lacking or may not be adjusted to the correct time zone. That's why our systems look at several factors to come up with what we consider to be our best estimate of when a page was published or significantly updated.
> Google determines a date using a variety of factors, including but not limited to: any prominent date listed on the page itself or dates provided by the publisher through structured markup.
> Google doesn't depend on one single factor because all of them can be prone to issues. Publishers may not always provide a clear visible date. Sometimes, structured data may be lacking or may not be adjusted to the correct time zone. That's why our systems look at several factors to come up with what we consider to be our best estimate of when a page was published or significantly updated.
https://developers.google.com/search/blog/2019/03/help-googl...