The watch continues to operate, even when it is not exposed to light. Leaving the watch in the dark can
cause the battery to run down, which will result in some watch functions to be disabled. If the battery
goes dead, you will have to re-conﬁ gure watch settings after recharging. To ensure normal watch
operation, be sure to keep it exposed to light as much as possible.
Battery charges in the light.
(Converts light to
The actual level at which some functions are disabled depends on the watch model.
Frequent display illumination can run down the battery quickly and require charging. The following
guidelines give an idea of the charging time required to recover from a single illumination operation.
Approximately 5 minutes exposure to bright sunlight coming in through a window
Approximately about 8 hours exposure to indoor ﬂ uorescent lighting
Be sure to read "Power Supply" (page E-36) for important information you need to know when
exposing the watch to bright light.
About This Manual
Depending on the model of your watch, display text appears either as
dark ﬁ gures on a light background or light ﬁ gures on a dark background.
All sample displays in this manual are shown using dark ﬁ gures on a light
Button operations are indicated using the letters shown in the illustration.
Each section of this manual provides you with the information you need to
perform operations in each mode. Further details and technical information
can be found in the "Reference" section.
To recover from the sleep state
Operation Guide 5163 (OC)
Battery discharges in the dark.
Some or all
Congratulations upon your selection of this CASIO watch. To get the most out of your purchase, be sure
to read this manual carefully.
Note that CASIO COMPUTER CO., LTD. assumes no responsibility for any damage or loss suffered by
you or any third party arising through the use of this product or its malfunction.
Keep the watch exposed to bright light
The electricity generated by the solar cell of the watch is stored by a built-in
battery. Leaving or using the watch where it is not exposed to light causes
the battery to run down. Make sure the watch is exposed to light as much as
When you are not wearing the watch on your wrist, position the face so it is
pointed at a source of bright light.
You should try to keep the watch outside of your sleeve as much as
possible. Charging is reduced signiﬁ cantly if the face is even only partially
If the display of the watch is blank...
If the display of the watch is blank, it means that the watch's Power Saving function has turned off the
display to conserve power.
See "Power Saving Function" (page E-50) for more information.
E-10 Radio Controlled Atomic Timekeeping
To specify your Home City
To perform manual receive
To check the latest signal reception results
E-24 World Time
To view the current time in another time zone
To toggle a city code time between Standard Time and Daylight Saving Time
To swap your Home City and World Time City
To measure times with the stopwatch
To conﬁ gure countdown start time and auto-repeat settings
To use the countdown timer
To set an alarm time
To turn an alarm on and off
To turn the Hourly Time Signal on and off