Google announced the May 2022 core update on May 25, 2022, around 11:30 am ET, with the blog post "May 2022 core update releasing for Google Search".
It was the first core update in more than six months, following the November 2021 core update. Google estimated it would take about 1-2 weeks to fully roll out.
Search Central announced completion on Twitter on 9th Jun 2022, 15 days after launch.
Unlike some rollouts that build slowly, this one moved early and hard. Data providers described it as a big update that rolled out quickly for many of the queries they tracked.
It read as noticeably more significant than the November 2021 core update. The heaviest ranking swings of the rollout were recorded around 5th Jun.
Google's framing at launch was the standard core-update message: these are changes "to improve Search overall and keep pace with the changing nature of the web", nothing in them targets specific sites, and "a negative rankings impact may not signal anything is wrong with your pages".
If your site moved in the May 25 to 9th Jun window, audit the affected pages. Check them against the self-assessment questions in Google's core updates help pages.
Some recovery can show between updates, but the biggest changes tend to register at later core updates.
Our recovery guide covers the sequence.