Work Time Tracking Calendar for Jira can be launched from a project context.
Starting the app version 6.1, all calendars accessible to a user are always displayed and can be selected in a project context view.
As of the version v 6.0.x, a calendar that is launched in a project context view shows the events that are based on sources which are configured for a given project or with the option "All projects".
You can create new calendars or edit existing ones without leaving the project context. The main buttons are accessible, assuming you have the required permissions.