Google confirmed on 13th Mar 2019 that "this week, we released a broad core algorithm update, as we do several times per year". Danny Sullivan confirmed the rollout had started on 12th Mar.
Google did not announce an end date. Formal rollout-complete notices were not yet standard practice in 2019.
The naming is what made this update historic. Brett Tabke, owner of WebmasterWorld and Pubcon, dubbed it "Florida 2" because a Pubcon Florida conference was under way.
The name was a nod to the original 2003 Florida update. But Search Engine Land stressed the two were unrelated algorithms.
On 15th Mar Google stepped in with an official name: "Our name for this update is 'March 2019 Core Update.' We think this helps avoid confusion; it tells you the type of update it was and when it happened." Every core update since has followed that month-and-year structure.
Google's recovery guidance was already the familiar one: "there's no 'fix' for pages that may perform less well other than to remain focused on building great content."
If a site moved during this window, the standing advice in Google's core updates help pages applies. Our recovery guide covers the sequence.
