What is the Calendar tool?
From EdTech Help
The Calendar tool allows instructors or site organizers to post events in a calendar format. The calendar has day, week, month, year, and simple list views.
The Calendar can be used to post important dates in a class, such as start and end dates, assessment dates, etc.
Project sites may use Calendar to post key dates, such as deadlines.
All calendars from all sites you have access to are merged in your Home Calendar.