Sep17 6am UTC - Sep18 6am UTC totals: 89 layoffs, 24 additions.
September totals (except Sep01): 4946 layoffs, and 568 additions.
Methodology and day-by-day breakdown is in comments.
EMEA started getting invites and mass layoff process officially kicked off in some locations. However, due to labor laws it will take several weeks before specific people are cut and lose access to Slack, so Slack totals won't reflect it for a long time.