To prevent Sales from booking more jobs on a given day, go to the dispatch calendar, select the day with the calendar icon, and then click the lock button for each project type you'd like to lock sales from booking jobs for
Then, if you try to book a new job using this date, Supermove will block it and indicate that this day has been locked.
To reverse this, go back to the same day on the dispatch calendar, and click the lock icon again to unlock booking.
Keep in mind that locking only prevents new jobs from being booked. Existing jobs will remain on the calendar.