Here are some legal holidays in Korea. Aside from New year and Christmas Day, you may check in here some dates and what occasions Koreans do celebrate.
March 1-Samil Independence Movement Day
April 5 – Arbor Day
May 5- Children’s Day
June 6 – Memorial Day
July 17 – Constitution Day
August 15 – Liberation Day; Thanksgiving Day
October 3 – National Foundation Day
If you know other holidays that are not listed here, you may send your comments.