The example calendars can be copied to your vault directly.

There is only one frontmatter property used in Gantt calendars. It defaults to gantt-calendar-definition.
You may have to rename this property when copying these calendars to your vault.

All example calendars include inline comments for guidance.
Comments are everything behind the '#' symbol.
You may safely remove everything from the '#' symbol onward.

For this plugin, all calendars are day-based; there is no time of day support.
This may change later, see Roadmap for planned features.