E-91 Using the Alarm
To enter the Alarm Mode
To set an alarm time
To turn an alarm and the Hourly Time Signal on and off
To stop the alarm
E-95 Checking the Current Time in a Different Time Zone
To enter the World Time Mode
To view the time in another time zone
To specify standard time or daylight saving time (DST) for a city
To turn on illumination manually
To change the illumination duration
To turn the auto light switch on and off
E-101 Other Settings
E-101 To turn the button operation tone on and off
E-102 To turn Power Saving on or off
E-109 Speciﬁ cations
Allowing the watch to become very hot can cause its liquid crystal display to black out. The
appearance of the LCD should become normal again when the watch returns to a lower temperature.
Turn on the watch's Power Saving function (page E-13) and keep it in an area normally exposed to
bright light when storing it for long periods. This helps to ensure that power does not run down.
Storing the watch for long periods in an area where there is no light or wearing it in such a way that it is
blocked from exposure to light can cause power to run down. Expose the watch to bright light
You can get an idea of the watch's power level by observing the battery power indicator on the display.
Battery Power Indicator Function Status
If all of the battery power indicators (H, M, L) are ﬂ ashing and the CHG (charge) indicator also is
ﬂ ashing, it means the battery level is very low. Expose the watch to bright light as soon as possible.
Even if battery power is at Level 1 (H) or Level 2 (M), the Digital Compass Mode, Barometer/
Thermometer Mode, or Altimeter Mode sensor may be disabled if there is not enough voltage available
to power it sufﬁ ciently. This is indicated when all of the battery power indicators (H, M, L) are ﬂ ashing.
Frequent ﬂ ashing of all of the battery power indicators (H, M, L) probably means that remaining battery
power is low. Leave the watch in bright light to allow it to charge.
Exposure Level (Brightness)
Outdoor sunlight (50,000 lux)
Sunlight through a window (10,000 lux)
Daylight through a window on a
cloudy day (5,000 lux)
Indoor ﬂ uorescent lighting (500 lux)
*1 Approximate amount of exposure time required each day to generate enough power for normal daily
*2 Approximate amount of exposure time (in hours) required to take power from one level to the next.
The above exposure times all are for reference only. Actual exposure times depend on lighting
For details about the operating time and daily operating conditions, see the "Power Supply" section of
the Speciﬁ cations (page E-112).
Radio Controlled Atomic Timekeeping
This watch receives a time calibration signal and updates its time setting accordingly. However, when
using the watch outside of areas covered by time calibration signals, you will have to adjust the settings
manually as required. See "Conﬁ guring Current Time and Date Settings Manually" (page E-30) for more
This section explains how the watch updates its time settings when the city code selected as the Home
City is in Japan, North America, Europe, or China, and is one that supports time calibration signal
If your Home City Code setting is this:
LIS, LON, MAD, PAR, ROM, BER, STO, ATH, MOW
TPE, SEL, TYO
HNL, ANC, YVR, LAX, YEA, DEN, MEX, CHI, NYC, YHZ,
The areas covered by MOW, HNL and ANC are quite far from the calibration signal transmitters, so
certain conditions may cause reception problems.
When HKG or BJS is selected as the Home City, only the time and date are adjusted according to the
time calibration signal. You need to switch manually between standard time and daylight saving time
(DST) if required. See "To conﬁ gure Home City and summer time settings" (page E-28) for information
about how to do this.
Operation Guide 3414
All functions enabled.
All functions enabled.
Auto and manual receive, illumination,
beeper, and sensor operation disabled.
Level Change *2
– – –
The watch can receive the signal from the transmitter
Anthorn (England), Mainﬂ ingen (Germany)
Shangqiu City (China)
Fukushima (Japan), Fukuoka/Saga (Japan)
Fort Collins, Colorado (United States)
Charging the Watch
The face of the watch is a solar panel that generates power from light. The generated power charges a
built-in rechargeable battery, which powers watch operations. The watch charges whenever it is exposed
Whenever you are not wearing the
watch, leave it in a location where it
is exposed to light.
Best charging performance is
achieved by exposing the watch to
the strongest light available.
Leaving the watch in bright light for charging can cause it to become quite hot.
Take care when handling the watch to avoid burn injury. The watch can become particularly hot
when exposed to the following conditions for long periods.
On the dashboard of a car parked in direct sunlight
Too close to an incandescent lamp
Under direct sunlight
Battery Power Indicator Function Status
– – –
The ﬂ ashing LOW indicator at Level 3 (L) tells you that battery power is very low, and that exposure to
bright light for charging is required as soon as possible.
At Level 5, all functions are disabled and settings return to their initial factory defaults. Once the battery
reaches Level 2 (M) after falling to Level 5, reconﬁ gure the current time, date, and other settings.
Display indicators reappear as soon as the battery is charged from Level 5 to Level 2 (M).
Leaving the watch exposed to direct sunlight or some other very strong light source can cause the
battery power indicator to show a reading temporarily that is higher than the actual battery level. The
correct battery level should be indicated after a few minutes.
All data stored in memory is deleted, and the current time and all other settings return to their initial
factory defaults whenever battery power drops to Level 5 and when you have the battery replaced.
Power Recovery Mode
Performing multiple sensor, illumination, or beeper operations during a short period may cause all of
the battery power indicators (H, M, and L) to start ﬂ ashing on the display. This indicates that the watch
is in the power recovery mode. Illumination, alarm, countdown timer alarm, hourly time signal, and
sensor operations will be disabled until battery power recovers.
Battery power will recover in about 15 minutes. At this time, the battery power indicators (H, M, L) will
stop ﬂ ashing. This indicates that the functions listed above are enabled again.
When turned on, Power Saving enters a sleep state automatically whenever the watch is left for a certain
period in an area where it is dark. The table below shows how watch functions are affected by Power
For information about enabling and disabling power saving, see "To turn Power Saving on and off"
There actually are two sleep state levels: "display sleep" and "function sleep".
Elapsed Time in Dark
60 to 70 minutes (display sleep)
6 or 7 days (function sleep)
The watch will not enter a sleep state between 6:00 AM and 9:59 PM. If the watch is already in a sleep
state when 6:00 AM arrives, however, it will remain in the sleep state.
The watch will not enter a sleep state while it is in the Stopwatch Mode or Countdown Timer Mode.
To recover from the sleep state
Move the watch to a well-lit area, press any button, or angle the watch towards your face for reading (page
– – –
Approximate Reception Ranges
UK and German Signals
The Anthorn signal is
receivable within this area
Signals are receivable in the Taiwan area
when reception conditions are good.
When wearing the watch, make sure
that its face is not blocked from light
by the sleeve of your clothing.
The watch may enter a sleep state
(page E-13) if its face is blocked
by your sleeve even only partially.
Except for the current time and the CHG
(charge) indicator, all functions and display
All functions disabled.
Blank, with PS ﬂ ashing
Display is off, but all functions are enabled.
All functions are disabled, but timekeeping is
Blank, with PS not ﬂ ashing
North American Signal
For the Honolulu and Anchorage time zones, the
signal can be received when reception conditions