Generate dummy content

The calendars are missing events to display.

How to keep it populated with sample content?

Devel Generate works well for datetime fields, but generates dates in the past year.

How can I control the generated data?

Alter generated dates.

Datetime range fields generate 24 hours by default, so it's a multiday field and the start/end time is the same when displayed as a smart date time range.

Smart date fields are generated with a 1 hour duration, so a single day event with a time range.