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.
I use "day starts at midnight" and "day ends at midnight" along with "show 14 hours at a time". This allows me to see the entire working day and most of the evening at a time and scrolling up or down brings things that happen very early/late into view. (Sometimes I set the end time for stuff that happens at night a bit later than the real end time so it shows in my regular 0800 - 2200 hours (or so) window.) Try to avoid having too many all-day events or make those hidden, though, as they take away space from the day.
But don't worry about all of this too much: when you set your timezone to Korean time, everything will magically be between 0800 and 2200 again. :-)
If the text -> iCal script writers have spare time on their hands I have a feature request: allow users to select which working groups and BoFs they're interested in, and then generate a custom schedule that only list those sessions and the plenaries. (Upto 6 sessions simultaneously gets a bit overwhelming.) Also, leaving out the breaks probably makes for a cleaner look.