you may see the schedule through the website below.
https://sugang.snu.ac.kr/

related notice is as follows:
http://ece.snu.ac.kr/community/notice/sugang?bm=v&bbsidx=53172

Please, find the attached file to quota exceeding course registration request manual.
(붙임2)

as for the courses offered by ECE dept. (course number usually starts 430.***), note the period for quota exceeding course registration request as below. 

	date	hour
Quota exceeding course registration	03.03.Fri 08:30 ~ 03.07.Tue 18:00	(24 hours) it starts 08:30 on March 2nd Not on a first come first served basis	as for the undergraduate courses offered by ECE dept. (course number usually starts 430.***) , due date for quota exceeding course registration is March 7th (Tue) 18:00. if you miss the due date, there is no way to apply for the courses by Quota Exceeding system.	approval or rejection will be notified to you by e-mail on March 8th by the regulation of academic affairs in ECE dept.
	03.03.Fri ~ 03.09.Thu		as for the graduate courses offered by ECE dept. (course number usually starts 430.***) , period for quota exceeding course registration is from March 2nd. to March 8th.	instructor' approval 03.03~03.10.
	03.03.~03.13.		student's confirmation