Every Friday at Noon EST - Windmill will send you your accomplishments via Slack. Just like any interaction with Windy, you can respond to edit any of your accomplishments.
At 5pm EST - the Accomplishments are saved in Windmill and shared with your manager.
If you have access to Windmill, and want to retroactively change Accomplishments, you can do that directly from your profile. Just select the "Edit Accomplishments" button.