Suggested

Calendar editor.

I am very happy about the new Grand Prix. I hope you continue to add new Grand Prix. There is a slight inconvenience, after the introduction of new Grand Prix, hard every time to change the calendar.
Offered to the editor of the calendar of trails. The calendar editor must be up to the League administrator. You can use the calendar editor to select the order of the Grand Prix. Also, using the calendar editor, the administrator will be able to adjust the number of Grand Prix, choosing from a list of existing ones.

They said they'll add that once they add some tracks.  Unfortunately, they didn't specify how many this would be.

Many trucks are coming, after a while the league host will have the option to edit the calendar