andrewbevitt

Every Calendar +1 is a pluggable interface for displaying locally entered events and displaying syndicated calendar feeds.
You can use any calendar feed that is supported by the FullCalendar jQuery library (at time of writing this was only Google Calendar). The event colours are customisable for each event source and the plugin supports a pluggable maps interface for event locations (initially the plugin only provides a Google Maps implementation but many more can be added).
See https://docs.google.com/document/pub?id=1QwmBusfl0gfRVkIt_PomAI3reG3B8Ae45-xCt1Q0uFw for annotated documentation.
The plugin creates two custom post types: 
1) Events 
2) Calendars
A Calendar Post can contain as many event posts as you like and can also syndicate as many external calendars as you like.
Events can be labeled as feature events: feature events will be displayed on any calendar the administratos configure as a Featured Calendar. This is a great way to have local site calendars (for say a regional office) and a global calendar which shows feature events from the local sites. Events can be scheduled to repeat (see below for details).
Roles and Capbilities: If you can edit a calendar and have edit_others_posts for events then you can edit any event in that calendar. Otherwise you can only edit your own as per normal.
This plugin was written because I could not find a plugin that provided great events management, calendar integration and worked reliably.
There is a planned development roadmap:
<ul>
<li>Add support for extra calendar providers</li>
<li>Add more widgets</li>
</ul>

Every Calendar +1 for WordPress

A WordPress plugin that integrates calendars, repeating events, custom post types, maps, offsite linking and has widget support.

ishitaka

XO Event Calendar is a simple event calendar plugin.
<h4>Functions</h4>
<ul>
<li>Adds an event custom post type and taxonomy.</li>
<li>Supports custom post type template.</li>
<li>Displays holiday on the calendar.</li>
<li>Supports WordPress multisite.</li>
</ul>
<h4>Operating environment</h4>
The Blocks is available in WordPress version 5.8 and above.

XO Event Calendar

XO Event Calendar is a simple event calendar plugin.

Every Calendar +1 for WordPress vs XO Event Calendar