Non-JIRA events can be added to calendar which can be seen only in calendar where they were created. Select one day or period you need and select "New non-JIRA event":
The event will be added to current calendar. It has only one attribute - Name, can be moved, stretched and trimmed by drag&drop and deleted permanently.
- Event's name.
- Event's background color.
- Event's text color.
You can make changes in the event by clicking on it.