Hold A (about 10 o'clock position) button down until display flashes
then use D button (about 5 o'clock position) to cycle through the Time Zones until you get to the one you want
from the user manual press the button closest to the seconds display on watch . bottom right button in normal time display to switch between am / pm time or 24 hundred military time.
http://mygshock.com/casio-manual/548/
enlarge the internet browser display to read which button to press to change the time or date.
press button B top left button to go into change mode
press button C bottom left button to move to seconds or minutes or hours .
press button A bottom right button to advance the time
press button b top left button to go back to normal time display
