To disable / delete the “Birthdays” Calendar in office 365, you’ll need to sign into your webmail account and do the following:
- Open your mailbox by going to https://vcsowa.vcsny.com/owa
- Click the cog in the top right
- Click the “Calendar” link at the bottom right
- Navigate on the left-hand pane to “Other Calendars, Birthday calendar”
- Click the option “Turn off the birthday calendar”.
- Click Save at the top.