I think you also need to set preferences to include timezones (obviously)
and also you need to set when the day starts and ends. I have not figured
out what the right settings are yet. Tell us if you figure it out.
In iCal, you can set the timezone that you want to view by clicking on the timezone name in the upper right part of the display. If Asia/Seoul doesn't show up, click on Other and a map will pop up; click in the vicinity of Seoul on the map.