Set Start and End Date Fields. You can set different date custom fields for each calendar. Go to Calendar's Cog/Set Up and on the main page choose Start Date Custom field and End Date Custom Field. Here only existing date or date time custom fields can be selected from dropdown menu.

Create a Calendar. Any user can create an unlimited number of calendars.

Customise a Calendar. Any user who has edit calendar permission can set up a custom fields in calendar events and their legends.