SNU Office of Academic Affairs released 2012 academic calendar which has detailed schedule of important academic affairs like tuition period, scholarship application period, commencement days, etc.
2012 academic year begins on March 2 when spring semester couses begin, and it ends on 2013 February 28 after the winter break.
You can see it more online here. http://en.snu.ac.kr/academic/aca0401.jsp
SNU NOW Notice
SNU Notice
Notice
SNU Notice