Unscrew the winding crown and pull it out all the way. turn it in either direction to set the reference time using the 24-hour hand and the minute hand.
Push the winding crown back in and pull it out one notch. Turn it in either direction to set the local time. The hour hand moves in increments of one hour. Then push the winding crown back in and screw it down all the way.
Turn the bezel either direction according to the time difference between the reference time indicated by the 24-hour hand and the time in the third time zone. the 24-hour hand read against the bezel indicates the time in the third time zone.