If you have a Howard-Miller 625-236 atomic clock, do you need to change the time zone only or manually set the time?
To set the time zone, press Mode (furthest left on the back of the clock) to get to the Alarm Time Mode. Then press Set (2nd from the left) to change the time zone. Then press Adjust (the middle button) to select the correct time zone. Press Mode again to exit the settings mode. To manually set the time, you need to remove the battery from the clock. Then reinsert the battery after 30+ seconds. Press and hold Set until the hour begins to flash, then press Adjust to change the time. Press and hold to quickly change the hour. Then press Set to change to the minutes and use Adjust to set the current minutes. Repeat this routine to set the seconds, month, date and year. Press Mode to exit to the Time mode.
The manual is available here: http://www.theclockdepot.com/howard-miller-625-236-techtime-operations-manual.pdf
I hope this helps.