If you have access to a web server that supports WebDAV (World Wide Web Distributed Authoring and Versioning), you can publish your Outlook calendars on this server. This feature is useful if you want to share calendars and information with other users and that you do not have a dedicated application such as Microsoft Exchange.
WebDAV is an extension of HTTP (HyperText Transfer Protocol) which allows you to create and edit documents on a web server. The server administrator or ISP can tell you if WebDAV is supported on the server you want to use or not.
Publishing calendars on Office Online represents a more flexible option. When a calendar is published to a web server, it is impossible to restrict its access. Restrictions are only possible through access permissions (to files and server). Configuration and management may require the intervention of the server administrator.
Here's how to publish a calendar on a WebDAV server:
From the Calendar, go to the Navigation Pane, right-click on the calendar you want to share.
In the context menu, select "Publish to Internet" and then click "Publish to WebDAV server".
In the Location box, type the location of the web server.
Select the number of days for which you want to share your calendar.
Click on the arrow next to Details and select the amount of detail you want to share.
Once the calendar is shared, its icon in the navigation pane, will changed.