Academic course repeats every week and every term. Succinct terminology to tell one from the other?

I am participating in an academic course that is multiple weeks long (the course spans a full term / a full semester). In some years, the whole course is offered multiple times a year (every term / every semester), in some years it is not. Successful completion of the course is a small part of completing a degree program.

I am looking for terminology to use in place of the bold words below.

Two things that are repeating:

• two times per week, a date/session/… of the course is taking place
• every third term, a new iteration/run/… of the course is taking place

Ideally, the terminology should be both succinct and unambiguous. For example, I’d like to be understood as not being able to attend a session as opposed to not being able to attend an entire iteration.

I am sure such terminology already exists, particularly in an academic setting, but without knowing what words to look for I am stumped.