Why has March 9th been chosen as the anniversary date for Covid.

The first known cases at that time in the U.K. were confirmed 31st January.

First known death (at that time) 5th March.

Pandemic declared on 11th March by WHO

Lockdown in U.K. 23rd March.

March 9th seems somewhat random unless we are using the overwhelming of Lombardy and Italy’s lockdown as the beginning of our covid? 

Don’t @ me with covid isn’t real etc-not interested.