Casio 4757 - Manual (Page 3)

Operation Guide 4757
3
Timekeeping
Use the Timekeeping Mode to set and view the current time and date. This section
also explains how to set the current date and time manually.
• If you become confused and lose your way during the following procedures, simply
put the watch down and do not perform any button operation for two or three
minutes. This will cause the watch to enter the Timekeeping Mode (indicated by
normal one-second movement of the second hand) automatically. After that, you can
try performing the manual setting procedure again from the beginning.
• All of the operations in this section are performed in the Timekeeping Mode, which
you enter by pressing C.
Hour hand
Minute hand
Day of week
Second hand
Press B.
Time zone
B
B
Date
Press C.
Auto Receive Month Day
Hour Seconds Time zone
Minutes
DST
Year
To set the time and date manually
1. In the Timekeeping Mode, hold down B until the Time
Zone starts to flash, which indicates the setting screen.
• The analog hands do not move in the setting screen.
2. Press C to cycle through settings in the sequence shown
below.
I I I I
II
II II II
II
I I
3. Select the setting you want to change, and then use A to change it as shown
below.
Screen Do this:
Press A.
Press A.
Press A.
Press A.
Press A.
Press A.
Press A.
To do this:
Cycle through time zones
Toggle between Auto DST (
), Standard Time ( ), or
Daylight Saving Time ( )
Reset the seconds to
Change the hour
Change the minutes
Change the year
Change the month
• For full information on time zones, see the “Time Zone Table”.
• When setting the day, the watch automatically will skip days (30 and 31) that are
not included in the currently selected month. If you can’t select 30 or 31 when you
want to, check to make sure that the proper month is selected.
4. Press B to exit the setting screen.
• This will cause the hands to move to the current time, and resume normal movement.
• The current time will be shown on the digital display while the hands are moving.
• It can take as long as about 11 minutes for the hands to reach the proper time
setting.
Change the day
Toggle signal auto receive on ( ) and off ( )
(This setting is possible only for time zones that support
time calibration signal reception.)
Press A.
Press A.
Note
• The auto receive setting is used for time calibration signal reception only. See “About
Auto Receive” for details.
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 signals include 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 signals.
• The default DST setting is Auto DST ( ) whenever you select +0, +1 or +2 as your
Home Time Zone.
• Auto DST ( ) can be selected only while +0, +1 or +2 is selected as the Home
Time Zone.
• 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 B until the currently selected time zone
appears on the display. This is the setting screen.
2. Press C and the DST setting screen appears.
3. Use A to cycle through the DST settings in the sequence shown below.
4. When the setting you want is selected, press B to exit the setting screen.
Auto DST ( ) DST on ( ) DST off ( )
Scrolling
A is used in various modes and setting screens to scroll through data. In most cases,
holding down A during a scroll operation scrolls through the data at high speed.
Radio-controlled Atomic Timekeeping Precautions
• Strong electrostatic charge can result in the wrong time being set.
• 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 update the date and day of the week automatically for the
period January 1, 2000 to December 31, 2099. Setting of the date by a 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.
• If you are in an area where proper time calibration signal reception is impossible, the
watch keeps time within ±20 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 time zone, DST (summer time), and
auto receive settings. The following are the initial factory defaults for these settings.
Time zone
DST (summer time)
Auto receive
Setting Initial Factory Default
(GMT+1)
(Auto switching)
(Auto receive)
Transmitters
This watch is designed to receive the time calibration signal transmitted from
Mainflingen, Germany and the signal from Rugby, England. You can configure the
watch to automatically select the transmitter that has the strongest signal.
In this case:
The first signal auto search operation
after factory default settings are in effect,
or after the time zone has been changed
Any case other than the above The watch does this:
1. Checks the Mainflingen signal first.
2. If the Mainflingen signal cannot be
received, checks the Rugby signal.
1. Checks the last successfully received
signal first.
2. If the last successfully received signal
cannot be received, checks the other
signal.
Timekeeping
• Resetting the seconds to 00 while the current count is in the range of 30 to 59 causes
the minutes to be increased by 1. In the range of 00 to 29, the seconds are reset to 00
without changing the minutes.
• The year can be set in the range of 2000 to 2099.
• The watch’s 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 watch’s battery replaced.
• The current time for all time zones in the Timekeeping Mode is calculated in accordance
with the Greenwich Mean Time (GMT) differential of each zone, based on your Home
Time Zone time setting.
• GMT differential is calculated by this watch based on Universal Time Coordinated
(UTC*) data.
* UTC is the world-wide scientific standard of timekeeping. It is based upon carefully
maintained atomic (cesium) clocks that keep time accurately to within microseconds.
Leap seconds are added or subtracted as necessary to keep UTC in sync with the
Earth’s rotation. The reference point for UTC is Greenwich, England.
Illumination Precautions
An LED (light-emitting diode) illuminates the face of the watch for easy reading in the
dark. In any mode (except when a setting screen is on the display), press A to illuminate
the face of the watch for about one second.
• The illumination provided by the light may be hard to see when viewed under direct
sunlight.
• Illumination automatically turns off whenever an alarm sounds.
• Frequent use of illumination can shorten the battery operating time.
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
• The watch automatically returns to the Timekeeping Mode if you do not perform any
button operation for one or two minutes while in the Receive Result Mode.
• The watch automatically returns to the Timekeeping Mode if you do not perform any
button operation for two or three minutes while in the Alarm or Home Position Adjustment
Mode.
• If you do not perform any operation for two or three minutes while a setting screen is
selected, the watch will exit the setting screen automatically.