This article sets out how to limit intake dates for specific courses
On a course the intake months can be added, navigate to the Course menu item:
Click on Courses and a list of all the courses will display:
Search for the desired Course and open the course:
Click on edit to set the intake months:
Select the Enrollment Start Calendar Months and click on Save:
This will limit the intake months on the enrollment's course if this is setup on the Course