Hi. How do I turn off the

Atomic clocks have antennas that are directional and reception may be improved by turning the antenna to increase signal strength. Place the radio controlled clock along a wall or near a window that faces towards Fort Collins. Locate atomic wall clocks at least 4-8 feet away from computer monitors.

Atomic Clock Synchronization (weathershack.com)

I would try replacing the battery in your watch to see if it comes back to life. So-called "atomic watches" have tiny radio receivers in them that periodically listen for the official atomic time being broadcast via WWVB in Colorado. However, as you might imagine, it takes a lot more power to operate a radio receiver than it does to power a typical quartz wristwatch, and even with larger-capacity or double batteries, it's been my experience that these watches burn through batteries more quickly than traditional "set them yourself" watches.
An additional factor is that a watch that cannot find the WWVB signal will scan for long periods of time before putting its radio receiver into hibernate mode. So, if your watch has been stored in a basement, an interior room in a large building, or some other place where a radio signal can't penetrate, that would also shorten the watch's battery life.

It's depends on where you are. For instance, where there is no time signal radio station, your (radio-controlled) watch can't turn itself (adjusted to atomic time).

Place the watch near a window that faces Colorado. best reception is at night although you should get a signal during the day where you are. The signal comes from a transmitter in Colorado. Also, make sure your watch is a model with the US frequency as there are different frequencies used in other parts of the world. Read more at http://www.ntp-time-server.com/atomic-clock.htm.

The watch will set itself at specific time set times, this is likely to be at 0200 0400 and 0600.
You will however be required to set the time zone, the switch is likely to be on the back.
INFO:
Atomic Time Synchronisation:
How does it work.
SHORT VERSION:
Radio set clocks and watches receive a 60-kilohertz, radio signal from the NIST the official timekeeper for the US and is located in Boulder, Colorado. Ft. Collins. they use atomic clocks and transmits this official time via high frequency short-wave and low frequency AM radio signals, satellite transmission, Internet, and via telephone.

REFERANCE LINKS:
OFFICAL TIME:
http://www.time.gov/timezone.cgi?Eastern/d/-5/java
PHOTO OF ANTANA TRANSMITTERS:
http://tf.nist.gov/stations/wwvb.htm
R/
David
http://antiqueclock.clockstop.com/

If you go to their web site (world.casio.com) you will be able to download a manual after entering the module number on the back of you watch.

There is a button with an atomic time symbol below the face of the watch. Press and hold this button until you hear a beep and the light will go off. To turn it back on again, just press and hold that same button until you hear a beep and it will come back in automatically when you tilt your watch.

The Atomic watches set date & time automatically. The general instruction book applies to the alarm & chronograph features.

http://www.invictawatch.com/support_files/instruction_manual/Manual-HiRes.pdf

The attached URL worked for me:
http://www.ccrane.com/instruction-manuals/e-howard-and-co-atomic-watch-eh23sa.pdf