In this article, I’d deal with how to add a Calender App to Office 365 E3 public SharePoint site. I came across this scenario when I was designing an Office 365 public facing site for the User Group in Chennai. When you subscribe for an Office 365 E3 subscription, you’ll get a public facing Sharepoint site.
You’ll see a Calender App missing in the Site Contents when you try to add an App. You need to employ an work around to achieve this one.
Add Custom List App
Go to List Settings –> Advanced Settings –> Enabled Management of Content Types
Add from existing Site Content Types
Change new button order and default content type and set Event as default content type
Now we have added the Calender App and we create events here.