Both Programs and Centers on campus undergo reviews led by the Office of the Provost every five years. The Provost has begun sending copies of the program reviews to the head of the Research Services department, who is forwarding them directly to the appropriate selectors.
See the University Registrar's Academic Calendar for the semester start/end dates, but also other internal deadlines such as grades being due, registration dates, last day to add/drop, etc.
Faculty proposing a new course fill out a detailed form that originates and ends with the Registrar's office, but which undergoes a workflow of various approvals, depending on the level and category of course (e.g., undergraduate "Topics" courses undergo less review but Graduate Faculty Senate must approve graduate-level "Topics" courses.)
Deadlines for submitting the form are December 10 for the following summer or fall term and June 15 for the next spring term. Usually, it takes close to two years to get a new course approved AND added to the departmental teaching rotation. Faculty think of a course they want to teach; they propose it to their department and get approval during a faculty meeting, and then start filling out the registrar's form.
This process is separate from getting a course approved for the Writing Intensive designation, which is done after the course itself is approved. The committee that approves WI courses meets several times a year to approve courses; ideally this approval should go through well ahead of time, but in some cases WI approval may occur as late as shortly before classes start for the semester.