The page has four different dates

Checks

• Data update date newer than any real change markup_modified_date_newer_than_any_real_change
• Shown date older than the date in data visible_date_older_than_markup
• Same update date on every page lastmod_identical_everywhere
• Date changes while content stays the same date_changes_without_content_change
• Published date is after the update date published_after_modified

Findings

• A page's date moved while its text stayed the same
• The dates a page declares contradict each other or the changes we observed

What this relies on

The detected change history is the truth.

How to verify by hand

Our own snapshots; no outside source needed.