The onColumnMoved event is fired when a user completes drag and drop moving of calendar columns (on drop).
At this point, the array with calendar columns (columns.list property) is already updated and stores the updated hierarchy. See also the onColumnMove handler which is called before the new positions are stored.
Available in the calendar component since version 2022.3.5381.
DayPilot.Calendar.onColumnMoved(args);