I suggested one course listing (rather than separate listings for summer and winter) and created a prototype for review in which each listing included a new line "offered in:" with appropriate values based on the arrays in the courses_offered file.
Then I asked if they'd like to be able to list courses by actual sessions offered (sep-apr, sep-dec, jan-apr, may-aug) and they said yes, so I:
- added new array variables to the courses_offered and courses_taught files (one for each of the four sessions)
- rewrote substantial chunks of the php code that figures out if a specific course is offered by the department (for use in grad and undergrad courses pages) and by specific instructors (for use in specific professor pages).
- documented the code and tested it
The site now requires that the dept provide lists of courses offered in each of 4 sessions rather than 2, for the overall department and for each instructor.