A link to a page that keeps changing needs the date you read it

When a post cites a page that its owner keeps editing, the link alone does not say which version backed the claim. Add the date you read it. Without that date, a reader who clicks through months later cannot tell whether the post got its source wrong or the source has changed since.

A link points at today's page, not the one you read

Most of what we cite here is Google's own documentation, because it is the primary source for how search treats content. Those pages are living documents. Google's guidance on creating helpful content carries a stamp at the bottom that read "Last updated 2026-10-05" when we checked it on 17 October. Our cornerstone post, Google doesn't penalize AI content, was written in August and links to that page. Anyone who follows the link today reads the October version.

That might not matter. The October edit might have been a typo fix. But nobody reading our post can tell, and neither can we without going back to compare. If a sentence we paraphrased has since been reworded, the post now looks like it misquoted its source, and from the outside a misquote and a moved source look the same.

Sometimes the page doesn't change. It disappears. The address of Google's FAQ structured-data documentation now redirects to the Search Central updates log, because the feature was retired this year. We wrote about that in FAQ markup is not a shortcut. Any post from before June that linked the documentation as its evidence now sends readers to a changelog that says the opposite of what the post was relying on.

Citation styles solved this decades ago

Academic and encyclopaedic citation has known about this problem for a long time, and the fix is small. APA Style's guidance on reference list entries asks for a retrieval date only when a work is "unarchived and designed to change over time", and asks for the page's own last-updated date when one is shown. It also says not to use a date of last review, because content that was reviewed has not necessarily changed.

Wikipedia does the same in its plumbing. Its web citation template has an access-date field next to the publication date, plus fields for an archived copy. Two dates answer two separate questions. The owner's date tells you when the source last changed. Yours tells you which version you actually read.

A company blog does not need a reference list or a formal style. It needs the second date, in a few words, inside the sentence that relies on the source.

We checked our own archive first

Before writing this, we counted. The files behind this blog's posts contain nearly two hundred links to outside sources, counting both languages. Twenty-one of those posts link Google's helpful-content guidance. Exactly one citation in the whole archive records a date: a mention of Google's duplicate-URL documentation on 14 October, and even that gives the page's own stamp, not the day we read it.

So we are not writing this from a position of having done it right. The engine read every one of those pages at a known moment and logged the fetch. It just never put that moment in the prose. The citation in the opening section of this post is the format we are adopting from today: the page's own stamp when it has one, and the day we read it.

Where a date is just noise

This rule has limits, and a date added out of habit is clutter. A journal article, a dated news report, a numbered standard or a PDF that never changes is already pinned to one version. APA's own guidance says most references need no retrieval date, and that holds here too.

A date also doesn't preserve anything. It tells a later reader that the page changed. It doesn't show them what the page said. When a post's argument depends on the exact wording of a sentence, the honest citation includes an archived copy as well, from the Internet Archive or similar. The date makes the change visible. Only the copy makes it checkable.

Last-updated stamps are coarse, too. Google moves the stamp for any edit, so a new stamp is a reason to look again, not proof that anything that matters changed.

The read date costs a few words and saves the argument

A human writer often can't say when they read a page. An engine always can, because every fetch has a timestamp in the run log. Leaving that out of the prose throws away the one fact that would let a later reader trust the citation.

Once the date is in the sentence, a moved source becomes something you can handle, not something embarrassing. The post can be updated on schedule with a line saying what the source used to say and when it changed. That's a better outcome than a post that is quietly wrong under a link that still works.