Casio 2638 Watch User Manual


 
Operation Guide 2608 2638 2688
5
Daylight Saving Time (DST)
Daylight Saving Time (summer time) advances the time setting by one hour from
Standard Time. Remember that not all countries or even local areas use Daylight
Saving Time.
The time calibration signal transmitted from Fort Collins includes both Standard Time
and DST data. When the Auto DST setting is turned on, the watch switches between
Standard Time and DST (summer time) automatically in accordance with the received
time signal.
The default DST setting is Auto DST (
AUTO) whenever you select HNL, ANC,
LAX, DEN, CHI, or NYC as your Home City code.
If you experience problems receiving the time calibration signal in your area, it is
probably best to switch between Standard Time and Daylight Saving Time (summer
time) manually.
To change the Daylight Saving Time (summer time) setting
1. In the Timekeeping Mode, hold down A until the city code starts to flash, which
indicates the setting screen.
2. Press C and the DST setting screen appears.
3. Use D to cycle through the DST settings in the sequence shown below.
4. When the setting you want is selected, press A twice to exit the setting screen.
Reference
This section contains more detailed and technical information about watch operation.
It also contains important precautions and notes about the various features and
functions of this watch.
Auto Return Features
If you leave the watch in the Time Recorder Mode or Alarm Mode for two or three
minutes without performing any operation, it automatically returns to the
Timekeeping Mode.
If you leave a screen with flashing digits on the display for two or three minutes
without performing any operation, the watch automatically saves anything you have
input up to that point and exits the setting screen.
Data and Setting Scrolling
The B and D buttons are used in various modes and setting screens to scroll
through data on the display. In most cases, holding down these buttons during a scroll
operation scrolls through the data at high speed.
Initial Screens
When you enter the Alarm or World Time Mode, the data you were viewing when you
last exited the mode appears first.
Radio-controlled Atomic Timekeeping Precautions
Strong electrostatic charge can result in the wrong time being set.
Even when the watch is within the reception range of the transmitter, signal
reception is impossible if the signal is blocked by mountains or other geological
formations between the watch and signal source.
Signal reception is affected by weather, atmospheric conditions, and seasonal
changes.
The time calibration signal is bounced off the ionosphere. Because of this, such
factors as changes in the reflectivity of the ionosphere, as well as movement of the
ionosphere to higher altitudes due to seasonal atmospheric changes or the time of
day may change the reception range of the signal and make reception temporarily
impossible.
Even if the time calibration signal is received properly, certain conditions can cause
the time setting to be off by up to one second.
The current time setting in accordance with the time calibration signal takes priority
over any time settings you make.
The watch is designed to automatically update the date and day of the week for the
period January 1, 2000 to December 31, 2099. Setting of the date by the time
calibration signal cannot be performed starting from January 1, 2100.
This watch can receive signals that differentiate between leap years and non-leap
years.
Though this watch is designed to receive both time data (hour, minutes, seconds)
and date data (year, month, day), certain signal conditions can limit reception to time
data only.
Normally, the signal reception date shown by the Last Signal screen is the date data
included in the received time calibration signal. When only time data is received,
however, the Last Signal screen shows the date as kept in the Timekeeping Mode at
the time of signal reception.
If you are in an area where proper time calibration signal reception is impossible, the
watch keeps time within ±15 seconds a month at normal temperature.
If you have problems with proper time calibration signal reception or if the time
setting is wrong after signal reception, check your current city code, DST (summer
time), and auto receive settings. The following are the initial factory defaults for
these settings.
Auto DST (
AUTO
) DST off (
OFF
) DST on (
ON
)
Setting
City code
DST (summer time)
Auto receive
Initial Factory Default
NYC (New York)
DST (Auto switching)
AUTO
(Auto receive)
ON
Timekeeping
The day of the week is automatically displayed in accordance with the date (year,
month, and day) settings.
The year can be set in the range of 2000 to 2099.
The watchs built-in full automatic calendar makes allowances for different month
lengths and leap years. Once you set the date, there should be no reason to change
it except after you have the watchs battery replaced or when battery power drops to
Level 4.
The current time for all city codes in the Timekeeping Mode and World Time Mode is
calculated in accordance with the Greenwich Mean Time (GMT) differential for each
city, based on the your Home City time setting.
GMT differential is calculated by this watch based on UTC
*
data.
*
The letters UTC stands for Universal Time Coordinated, which is the world-wide
scientific standard of timekeeping. It is based upon carefully maintained atomic
(cesium) clocks that keep accurate to within microseconds. Leap seconds are
added or subtracted as necessary to keep UTC in sync with the Earths rotation.
The reference point for UTC is Greenwich, England.
12-hour/24-hour Timekeeping Formats
The 12-hour/24-hour timekeeping format you select in the Timekeeping Mode is also
applied in all other modes.
With the 12-hour format, the P (PM) indicator appears on the display for times in the
range of noon to 11:59 p.m. and the A (AM) indicator appears for times in the range
of midnight to 11:59 a.m.
With the 24-hour format, times are displayed in the range of 0:00 to 23:59, without
any indicator.
Power Saving Function
When turned on, the Power Saving function automatically enters a sleep state
whenever the watch is left in an area where it is dark for a certain period. The table
below shows how watch functions are affected by the Power Saving function.
Wearing the watch inside the sleeve of clothing can cause it to enter the sleep state.
The watch will not enter the sleep state between 6:00 AM and 10:59 PM. If the
watch is already in the sleep state when 6:00 AM arrives, however, it will remain in
the sleep state.
To recover from the sleep state
Perform any one of the following operations.
Move the watch to a well-lit area.
It can take up to two seconds for the display to
turn on.
Press any button.
Angle the watch towards your face for reading.
To turn Power Saving on and off
1. In the Timekeeping Mode, hold down A. This causes
the city code to flash, which indicates the setting
screen.
2.Press A again.
3. Press C seven times until the Power Saving on/off
screen appears.
4. Press D to toggle Power Saving on (
ONON
ONON
ON) and off
(
OFFOFF
OFFOFF
OFF).
5. After the setting is the way you want, press A to exit
the setting screen.
The Power Saving on indicator is on the display in all
modes while the Power Saving is turned on.
Backlight Precautions
The electro-luminescent panel that provides illumination loses power after very long
use.
The illumination provided by the backlight may be hard to see when viewed under
direct sunlight.
The watch may emit an audible sound whenever the display is illuminated. This is
due to vibration of the EL panel used for illumination, and does not indicate
malfunction.
The backlight automatically turns off whenever an alarm sounds.
Frequent use of the backlight shortens the battery operating time.
Auto light switch precautions
Wearing the watch on the inside of your wrist as well as movement or vibration of
your arm can cause the auto light switch to activate and illuminate the display. To
avoid running down the battery, turn off the auto light switch whenever engaging in
activities that might cause frequent illumination of the display.
The backlight may not light if the face of the watch is
more than 15 degrees above or below parallel. Make
sure that the back of your hand is parallel to the ground.
The backlight turns off in about one second, even if you
keep the watch pointed towards your face.
Static electricity or magnetic force can interfere with
proper operation of the auto light switch. If the backlight
does not light, try moving the watch back to the starting
position (parallel with the ground) and then tilt it back
toward you again. If this does not work, drop your arm
all the way down so it hangs at your side, and then bring
it back up again.
Under certain conditions, the backlight may not light
until about one second after you turn the face of the
watch towards you. This does not necessarily indicate
malfunction of the backlight.
You may notice a very faint clicking sound coming from
the watch when it is shaken back and forth. This sound
is caused by mechanical operation of the auto light
switch, and does not indicate a problem with the watch.
Elapsed Time
in Dark
60 to 70 minutes
6 or 7 days
Display
Blank, with Sleep indicator (S /
SLEEP
) flashing
Blank, with Sleep indicator (S
/
SLEEP
) not flashing
Operation
All functions enabled, except
for the display
Beeper tone, backlight, display,
and auto receipt of the
calibration signal are disabled.
l
l
l
l
l
l
l
l
l
l
l
l
Power saving on
indicator
More than 15 degrees
too high