Show the same date to people and machines

How to do it

Take both dates from the page data, so the visible date, the JSON-LD and the sitemap lastmod agree. Change dateModified only when the main content changes, never on every build. Give a time zone with any time, in the format Send dates as RFC 3339 with a time zone uses. Keep other dates on the page to a minimum, so search engines pick the right one.

Examples

HTML example

<p>Updated <time datetime="2026-09-14">14 September 2026</time></p>
<script type="application/ld+json">
{ "@context": "https://schema.org", "@type": "Article", "headline": "How to care for oak floors",
  "datePublished": "2026-03-02T09:00:00+01:00", "dateModified": "2026-09-14T10:30:00+02:00" }
</script>

JavaScript example

const visible = page.querySelector('time[datetime]').getAttribute('datetime');
const { dateModified } = JSON.parse(page.querySelector('script[type="application/ld+json"]').textContent);
assert.equal(dateModified.slice(0, 10), visible);
assert.equal(sitemapLastmod[url], visible);

Python example

visible = page.select_one("time[datetime]")["datetime"]
date_modified = json.loads(page.select_one('script[type="application/ld+json"]').string)["dateModified"]
assert date_modified[:10] == visible == sitemap_lastmod[url]

How to check

A build test reads each article. Its visible <time datetime> equals datePublished or dateModified, dateModified equals the sitemap lastmod, and no date is later than the build.

Sources

• Google Search Central – Influence the byline date

Related rules

• SEO-37 Show who wrote each page in SEO
• SEO-39 Update pages instead of republishing them in SEO
• API-7 Send dates as RFC 3339 with a time zone in API design
• DOC-32 Show the last-updated date on every docs page in Documentation