Make sure that https://fedoraproject.org/wiki/Marketing_F12_schedule doesn't conflict with the schedules for any other team.

Put the schedule in "Task YYYY-MM-DD (Start) YYYY-MM-DD (End)" format in a .txt document.

Email the .txt file to Marketing, the Fedora Program Manager (John Poelstra), and post it to https://fedoraproject.org/wiki/Marketing_F12_schedule (temporarily, until the FPM puts the final schedule up on a static page - then we'll link to that from the Marketing F12 schedule page instead, but that's a separate update task).