March 15 is the day people leave Twitter.
The abandonment of Twitter in the Musk era has, for now, been inconsistent and chaotic, with people leaving at different times and for different reasons.
An organized effort to promote a "Leave Twitter" day, when everyone still reluctantly there logs off for the last time, with enough advance to line up alternate sites, should help get people out.
Thus, March 15. The Ides of Musk. Spread the word.