Add Sejong (South Korea) to your list and use my-locations table to visually convert it's time to another timezone or city time.
Mouse over the colored hour-tiles and glance at the hours selected by the column.

Current time zone for Sejong (South Korea) is KST, whose offset is GMT+9 from Greenwich Mean Time (GMT).

The IANA timezone identifier for Sejong, South Korea is "Asia/Seoul"

It currently does not observe Daylight Savings Time.