By default, members are allowed to adjust their celebration dates. In the rare case that you'd like to not allow members to change their celebration dates, you can restrict members from changing their birthday and work anniversary.
Who can use this: Workspace Owners and Admins on the Basic plan and above, or on any plan during the free trial. Works the same for Slack and Microsoft Teams workspaces.
For an overview of the whole feature, read the Celebrations Guide.
Note: This advanced setting applies to all Matter users, including Owners and Admins.
Allow Members to Modify Their Celebration Dates
Open the Web App.
Go to Settings, then the Celebrations section.
Click Advanced Settings, then check or uncheck Allow members to modify their celebration dates.
Then hit Save.
