I’ve been MS student and completed all my courses in years 2012-2014, but instead of taking my master’s exam in 2014 (which is requirement for graduation) I took a break. I have defended my master’s thesis and passed the master’s exam this year. During this break out period I wasn’t student, so I am unsure how should I state this on my resume and make it look as good as possible.
I suggest stating the date ranges during which you were registered as a student, as well as the degree date:
SomeUniversity September 2012 to March 2014 and January 2018, MS SubjectX 2018.
That will presumably match up with the employment section of the CV that will show work during the gap.
Your date of graduation is the one written on your graduation certificate.
If you want to justify your absence, cover letter is the correct place. Not the CV.