Operation Guide 3583
EN-9
World Time Mode
C C
Countdown Timer Mode Alarm Mode
C
x In any mode (except when a setting screen is on the display), press B to illuminate
the display.
EN-8
Selecting a Mode
x Press C to change from mode to mode.
C C C
Timekeeping Mode Stopwatch Mode Preset Timer Mode
EN-7
Watch Features
You can also find information
about operational procedures
at the CASIO website.
https://s.casio.jp/mw/en/3583/
◆
Stopwatch
◆
Preset Timer
◆
Countdown Timer
◆
World Time
◆
Alarm
EN-6
To toggle a city code time
between Standard Time and Daylight Saving Time .................................... EN-33
To set the alarm time ......................................................................................... EN-34
To stop the alarm tone after it starts to sound .............................................. EN-35
To switch the Daily Alarm and Hourly Time Signal on and off ....................... EN-36
To test the alarm ................................................................................................ EN-36
To illuminate the display .................................................................................... EN-37
To turn the button operation tone on and off ................................................. EN-40
EN-5
Procedure Lookup
The following is a handy reference list of all the operational procedures contained in
this manual.
To set the time and date .................................................................................... EN-12
To toggle the Timekeeping Mode time between DST and Standard Time ... EN-14
To toggle between 12-hour and 24-hour timekeeping ................................... EN-15
To measure times with the stopwatch ............................................................. EN-17
To set the event time ......................................................................................... EN-19
To start timing at the beginning of an event ................................................... EN-19
To pause timing .................................................................................................. EN-20
To reset elapsed time measurement to zero ................................................... EN-20
To perform a preset timer operation ................................................................ EN-22
To configure countdown timer settings ........................................................... EN-26
To perform a countdown timer operation ........................................................ EN-30
To view the time for another city code............................................................. EN-32
EN-4
EN-3
Contents
About This Manual................................................................................................ EN-2
Watch Features ..................................................................................................... EN-7
Selecting a Mode .................................................................................................. EN-8
Timekeeping ....................................................................................................... EN-11
Stopwatch ........................................................................................................... EN-16
Preset Timer ........................................................................................................ EN-21
Countdown Timer ............................................................................................... EN-25
World Time .......................................................................................................... EN-32
Alarm ................................................................................................................... EN-34
Illumination .......................................................................................................... EN-37
Reference ............................................................................................................ EN-38
Specifications ..................................................................................................... EN-44
EN-2
About This Manual
x Button operations are indicated using the letters shown
in the illustration.
x 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.
EN-1
ENGLISH
You can also find information about
operational procedures at the CASIO website.
https://s.casio.jp/mw/en/3583/
MA2506-EA
© 2025 CASIO COMPUTER CO., LTD.
Published: 6/2025
Operation Guide 3583
EN-19
To set the event time
1. In the Stopwatch Mode, hold down A until the current
event time setting starts to flash in the lower display.
This is the setting screen.
x If the current event time is not displayed, use the
procedure under “To reset elapsed time measurement
to zero” (page EN-20) to display it.
2. While a setting is flashing, use D (+) and B (–) to
change it.
x You can set the event time in the range of 1 minute to
60 minutes, in 1-minute units.
x “- -” indicates there is no event time set.
3. Press A to exit the setting screen.
To start timing at the beginning of an event
When the current time in the lower display reaches the event start time, press D to
start timing.
x This will display elapsed time measurement in the upper and lower displays.
EN-18
Using the Watch for Official Timing of a Sport Event
After you set a game or event time, the watch will sound an alarm when the time in
the lower display reaches that time.
If the event is interrupted for some reason, you can press D to pause and resume
timing in the upper display. The lower display shows the total elapsed time since the
start of the timing operation. You can calculate the total amount of time that play was
interrupted (lost time or injury time) by subtracting the upper display time from the
lower display time.
EN-17
x This time measurement (1/100 second)
cannot be paused.
Elapsed Time Screen
Minutes Seconds
x Press D to pause and
resume elapsed time
measurement.
Minutes Seconds
x This time measurement
cannot be paused.
It shows the total elapsed
time since the timing
operation started.
To measure times with the stopwatch
Elapsed Time
D D D D
Hold down A
Start Stop*
1
Resume Stop*
1
Reset
*1 Elapsed time measurement in the lower display continues.
EN-16
Stopwatch
The stopwatch lets you measure elapsed time. The upper
display and lower display can be used for official timing of
an event or game.
x The measurement range of the upper display is
59minutes 59seconds.
x The measurement range of the lower display is
99minutes 59seconds.
x The stopwatch continues to run, restarting from zero
after it reaches its limit, until you stop it.
x The stopwatch measurement operation continues even if
you exit the Stopwatch Mode.
x All of the operations in this section are performed in
the Stopwatch Mode, which you enter by pressing C
(page EN-8).
Timekeeping Mode time
Initial Stopwatch Mode
Screen
EN-15
To toggle between 12-hour and 24-hour timekeeping
In the Timekeeping Mode, press D to toggle between 12-hour timekeeping and
24-hour timekeeping.
x With the 12-hour format, the P (PM) indicator appears for times in the range of noon
to 11:59 p.m. and no indicator appears to the left of the hour digits for times in the
range of midnight to 11:59 a.m.
x With the 24-hour format, times are displayed in the range of 0:00 to 23:59, without
any indicator.
x The 12-hour/24-hour timekeeping format you select in the Timekeeping Mode is
applied in all other modes.
x The P indicator is not displayed with the Timekeeping Mode time on the Preset
Timer Mode, Countdown Timer Mode, World Time Mode, and Alarm Mode screens.
EN-14
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.
To toggle the Timekeeping Mode time between DST and Standard Time
1. In the Timekeeping Mode, hold down A until the
seconds start to flash, which indicates the setting
screen.
2. Press C to display the DST setting screen.
3. Press D to toggle between Daylight Saving Time (On
displayed) and Standard Time (OFF displayed).
4. Press A to exit the setting screen.
x The DST indicator is on the display while Daylight Saving
Time is turned on.
DST indicator
EN-13
3. When the setting you want to change is flashing, use D and B to change it as
described below.
Screen To do this: Do this:
Reset the second to 00
Press D.
Toggle between Daylight Saving Time (On)
and Standard Time (OFF)
Change the city code
Use D (east) and B (west).
Change the hour or minute
Use D (+) and B (–).
Change the year
Change the month or day
x See “Daylight Saving Time (DST)” on page EN-14 for details about the DST
setting.
4. Press A to exit the setting screen.
EN-12
To set the time and date
1. In the Timekeeping Mode, hold down A until the
seconds start to flash, which indicates the setting
screen.
2. Press C to move the flashing in the sequence shown
below to select other settings.
Second DST City Code Hour
C C C C
C
Day
Month Year Minute
C C C
EN-11
Timekeeping
Use the Timekeeping Mode to set and view the current
time and date.
Read This Before You Set the Time and Date !
The times displayed in the Timekeeping Mode and World
Time Mode are linked. Because of this, make sure you
select a city code for your Home City (the city where you
normally use the watch) before you set the time and date.
x For full information on city codes, see the “City Code
Table” at the back of this manual.
Day of week
Second
Hour : Minute
PM indicator
Month – Day
EN-10
You can also find information about operational
procedures at the CASIO website.
https://s.casio.jp/mw/en/3583/
Operation Guide 3583
EN-29
4. While a setting is flashing, use D and B to change it as described below.
Screen To do this: Do this:
Change the countdown timer number
Use D (+) and B (–).
Change the minutes (00-59)
Change the seconds (00-55, 5-second units)
Toggle auto-repeat on ( ) and off ( )
Press D.
x Any timer whose start time is 00' 00" will not be used during the countdown
timer operation.
x There is no auto-repeat for individual countdown timers. In the Countdown Timer
Mode, auto-repeat repeats the entire set of timers.
EN-28
3. Press C to move the flashing in the sequence shown below to select other
settings.
Countdown timer numbers
Minutes Seconds Auto-repeat
C C C
C
EN-27
2. Use D (+) and B (–) to scroll through the countdown timer numbers until the one
you want to set is displayed.
INT 1
D
INT 2
D
INT 3
D
INT 4
D
INT 5
B B B B
INT 9
B
INT 8
B
INT 7
B
INT 6
D D D
D
B
BD
EN-26
x You can turn on an auto-repeat feature that restarts the timer sequence from the
beginning when the end of the last timer is reached.
x All of the operations in this section are performed in the Countdown Timer Mode,
which you enter by pressing C (page EN-9).
To configure countdown timer settings
1. In the Countdown Timer Mode, hold down A until the
countdown timer number starts to flash.
This is the setting screen.
EN-25
Countdown Timer
With the countdown timer, you can set up to nine start
times, which are counted down in sequence one after
the other.
The countdown timer can be used for interval training
(for example, three minutes running with INT 1, 1
minute rest with INT 2, five minutes running with INT 3)
or for timing an multi-period event (for example, 45
minutes of play with INT 1, 15 minutes rest with INT 2,
45 minutes play with INT 3).
x The watch performs an alert operation (beeper) when
any timer reaches zero.
x An alert operation (about one second) is performed
when any countdown timer (except for the last one
in the series) reaches zero. When the last countdown
timer in the series reaches zero, an alert operation is
performed for about five seconds.
Timekeeping Mode time
Start time
(Minutes Seconds)
Countdown timer
number
EN-24
x When the end of the countdown is reached, the alarm sounds for 10 seconds or
until you stop it by pressing any button.
x When the end of the countdown is reached while auto-repeat is turned off, the
watch will go into an elapsed time operation and display how much time has
elapsed since the end of the countdown was reached. The elapsed time operation
will stop automatically when it reaches 60 minutes. At that time the countdown
timer start time selection screen will appear.
x When the end of the countdown is reached while auto-repeat is turned on, a new
countdown starts from the selected preset start time. The number of repeats is
displayed in the lower display. The number of repeats display changes to “- -”
when the count reaches 100.
x To stop a countdown operation completely, first pause it (by pressing D), and then
press A. This will display the initial Preset Timer Mode screen.
EN-23
x To turn on auto-repeat, hold down A while a start
time selection screen is displayed. The number of
repeats will appear in the lower display.
x Frequent use of auto-repeat and the alarm can run
down battery power.
2. Press D to start the countdown timer.
x Press D while a countdown operation is in progress
to pause it. Press D again to resume the countdown.
Number of repeats
Auto-repeat on indicator
EN-22
To perform a preset timer operation
1. In the Preset Timer Mode, use A to scroll through the
preset times until the one you want to use is displayed.
10 minutes 12 minutes 15 minutes 20 minutes
A A A
A
A
25 minutes
45 minutes 40 minutes 35 minutes 30 minutes
A A A
A
EN-21
Preset Timer
The watch includes a number of different preset times
that you can select for the countdown start time.
An alarm sounds when the countdown reaches zero.
x The following are the preset start times, all in
minutes: 10, 12, 15, 20, 25, 30, 35, 40, 45.
x You can also select auto-repeat, which automatically
restarts from the preset start time you selected,
whenever zero is reached.
x All of the operations in this section are performed in
the Preset Timer Mode, which you enter by pressing
C (page EN-8).
Preset timer time
Timekeeping Mode time
EN-20
To pause timing
1. Press D.
This stops elapsed time measurement in the upper display.
x Elapsed time measurement in the lower display continues.
2. To resume elapsed time measurement in the upper display, press D again.
When the preset event time is reached
x The watch will sound an alarm when the elapsed time measurement in the lower
display (total elapsed time since timing started) reaches the preset event time.
x Elapsed time measurement continues to be performed even after the preset event
time is reached.
To reset elapsed time measurement to zero
1. Press D. This stops elapsed time measurement in the upper display.
x Elapsed time measurement in the lower display continues.
2. Hold down A until the initial Stopwatch Mode screen appears.
Operation Guide 3583
EN-39
Mode Graphic Area A Graphic Area B
Timekeeping Timekeeping Mode seconds Timekeeping Mode 10-seconds
Stopwatch Stopwatch Time 1/20-second Stopwatch Time 10-seconds
Preset Timer Preset Time 1/20-second Preset Time 10-seconds
Countdown Timer Countdown Time 1/20-second Countdown Time 10-seconds
World Time World Time Mode seconds World Time Mode 10-seconds
Alarm No indication No indication
EN-38
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.
Graphic Areas
The following describes the information indicated by the two graphic areas in each
mode.
Graphic area BGraphic area A
EN-37
Illumination
This watch has an LED (light-emitting diode) panel that
causes the entire display to glow for easy reading in the
dark.
x See “Illumination Precautions” (page EN-43) for more
important information.
To illuminate the display
In any mode, press B to turn on illumination.
EN-36
To switch the Daily Alarm and Hourly Time Signal on and off
Press D while in the Alarm Mode to change the status of the Daily Alarm and Hourly
Time Signal in the following sequence.
D D D
D
Both on Both off Daily Alarm only Hourly Time
Signal only
To test the alarm
Hold down D while in the Alarm Mode to sound the alarm.
EN-35
2. Press C to change the selection in the following sequence.
Hour Minute
C
3. While a setting is flashing, use D and B to change it as described below.
Screen To do this: Do this:
Change the hour and minute
Use D (+) and B (–).
x With the 12-hour format, set the time
correctly as a.m. or p.m. (P indicator).
4. After you set the alarm time, press A to return to the Alarm Mode.
To stop the alarm tone after it starts to sound
Press any button.
EN-34
Alarm
When the Daily Alarm is turned on, the alarm sounds
for 10 seconds at the preset time each day. When the
Hourly Time Signal is turned on, the watch beeps every
hour on the hour.
x All of the operations in this section are performed
in the Alarm Mode, which you enter by pressing C
(page EN-9).
To set the alarm time
1. Hold down A while in the Alarm Mode until the hour
digits start to flash on the display. The hour digits
flash because they are selected.
x This operation automatically turns on the alarm.
Hourly time signal
on indicator
Timekeeping Mode time
Alarm time (Hour : Minute)
Alarm on indicator
EN-33
To toggle a city code time between Standard Time and Daylight Saving Time
1. In the World Time Mode, use D to display the city code
(time zone) whose Standard Time/Daylight Saving Time
setting you want to change.
2. Hold down A for about one second to toggle between
Daylight Saving Time (DST displayed) and Standard
Time (DST not displayed).
x The DST indicator is on the display whenever you
display a city code for which Daylight Saving Time is
turned on.
x Note that the DST/Standard Time setting affects only
the currently displayed city code. Other city codes are
not affected.
DST indicator
EN-32
World Time
World Time shows the current time in 48 cities (29 time
zones) around the world.
x When you enter the World Time Mode, the data you
were viewing when you last exited the mode appears
first.
x All of the operations in this section are performed in
the World Time Mode, which you enter by pressing
C (page EN-9).
To view the time for another city code
In the World Time Mode, press D to scroll eastward
through city codes.
x For full information about city codes, see the “City
Code Table” at the back of this manual.
x If the current time for a city is wrong, check your
Timekeeping Mode time and Home city code settings
and make necessary changes.
Timekeeping Mode time
Current time in the zone of
the selected city code
City code
EN-31
x The first countdown timer of the series is the lowest numbered one with a start time
that is not zero. The final countdown timer of the series is the highest numbered
one with a start time that is not zero.
x While auto-repeat is turned off, the watch beeps when each countdown timer
reaches zero. An alarm will sound for about five seconds when the final countdown
timer reaches zero.
x While auto-repeat is turned on, the watch beeps once when each countdown timer
reaches zero. A five-second alert operation is performed when the final countdown
timer reaches zero, unless the start time of the final countdown timer is 10 seconds
or less. In such a case, the alert operation for the final countdown timer is only one
second long.
x Timing restarts from the first timer when the final countdown timer reaches zero.
The number of repeats is displayed in the lower display. The number of repeats
display changes to “- -” when the count reaches 100.
x An ongoing countdown timer operation continues to be performed even if you exit
the Countdown Timer Mode.
x To stop a countdown timer operation, first press D to pause the countdown of the
current timer, and then press A. This will display Countdown Timer 1 (INT 1).
EN-30
5. Set the times of all of the timers that you want.
6. Press A to exit the setting screen.
x When auto-repeat is turned on, the number of repeats
will appear in the lower display.
x Frequent use of auto-repeat and the alarm can run down
battery power.
To perform a countdown timer operation
In the Countdown Timer Mode, press D to start the countdown of the lowest
numbered countdown timer that has a start time setting that is not zero.
x To pause the countdown timer that is currently counting down, press D. Press D
again to resume the countdown.
x During a countdown timer operation, any countdown timer whose start time is zero
(00' 00") is skipped.
Number of repeats
Auto-repeat on indicator
Operation Guide 3583
EN-46
Battery: One lithium battery (Type: CR2025)
Battery nominal voltage: 3V
Approximately 10 years on type CR2025 (1 stopwatch elapsed time operation
per week (10-second alarm when timing reaches preset event time); 1 preset
timer operation per week (10-second alarm when countdown reaches zero); 1
countdown timer operation per week (8 1-second beeps when any countdown
timer reaches zero, 5-second alarm when last countdown timer reaches zero), daily
alarm operation 10 seconds per day, 1.5 seconds of illumination per day)
Specifications are subject to change without notice.
EN-45
Countdown Timer
Number of Timers: Up to 9
Measuring unit: 1 second
Input range: 59'55" (1-minute increments and 5-second increments)
Other: Auto-repeat timing
World Time: 48 cities (29 time zones)
Other: Daylight Saving Time/Standard Time
Alarm
Daily alarm
Setting units: Hours, minutes
Alarm tone duration: 10 seconds
Hourly time signal: Beep every hour on the hour
Illumination: LED (light-emitting diode)
Other: Button operation tone on/off
EN-44
Specifications
Accuracy at normal temperature: ±30 seconds a month
Timekeeping: Hour, minute, second, p.m. (P), month, day, day of the week
Time format: 12-hour and 24-hour
Calendar system: Full Auto-calendar pre-programmed from the year 2000 to 2099
Other: Home City code (can be assigned one of 48 city codes); Daylight Saving
Time (summer time)/Standard Time
Stopwatch
Measuring units: Upper display: 1 second; Lower display: 1 second
Measuring capacities: Upper display: 59'59"; Lower display: 99'59.99"
Measuring modes: Elapsed time, event time
Preset Timer
Measuring unit: 1 second
Preset Start Times: 10, 12, 15, 20, 25, 30, 35, 40, 45 minutes
Timer modes: Elapsed time, Auto-repeat
Measurement of elapsed time for up to 60 minutes after the countdown reaches
zero
EN-43
Illumination Precautions
x Illumination loses power after very long use.
x Illumination may be hard to see when viewed under direct sunlight.
x Illumination turns off automatically whenever an alarm sounds.
x Frequent use of illumination runs down the battery.
EN-42
x 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.
World Time
x The seconds count of the World Time is synchronized with the seconds count of
the Timekeeping Mode.
x All World Time Mode times are calculated from the current Home City time in the
Timekeeping Mode using UTC time differential values.
x The UTC differential is a value that indicates the time difference between a
reference point in Greenwich, England and the time zone where a city is located.
x The letters “UTC” is the abbreviation for “Universal Time Coordinated”, which 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.
EN-41
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 at high speed. This is true except when the countdown timer
number is flashing on the Countdown Timer Mode screen (page EN-26).
Auto Return Features
x If you leave the watch in the Alarm Mode for two or three minutes without
performing any operation, it changes to the Timekeeping Mode automatically.
x If you leave a screen with flashing digits on the display for two or three minutes
without performing any operation, the watch exits the setting screen automatically.
Timekeeping
x 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.
x The year can be set in the range of 2000 to 2099.
EN-40
Button Operation Tone
The button operation tone sounds any time you press one
of the watch’s buttons. You can turn the button operation
tone on or off as desired.
x Even if you turn off the button operation tone, the alarm,
the Hourly Time Signal, the countdown timer alarm, and
the event time alarm all operate normally.
To turn the button operation tone on and off
In any mode (except when a setting screen is on the
display), hold down C to toggle the button operation tone
on (
not displayed) and off ( displayed).
x Holding down C to turn the button operation tone on or off also causes the
watch’s current mode to change.
x
is displayed in all modes when the button operation tone is turned off.
Mute indicator
L-3
City
Code
City
UTC
Differential
Other major cities in same time zone
LIS Lisbon 0 Dublin, Casablanca, Dakar, Abidjan
LON London
BCN Barcelona +1 Amsterdam, Algiers, Hamburg, Frankfurt, Vienna,
Stockholm, Madrid
PAR Paris
MIL Milan
ROM Rome
BER Berlin
ATH Athens +2 Helsinki, Beirut, Damascus, Cape Town
JNB Johannesburg
IST Istanbul
CAI Cairo
JRS Jerusalem
MOW
Moscow +3 Kuwait, Riyadh, Aden, Addis Ababa, Nairobi
JED Jeddah
THR Tehran +3.5 Shiraz
L-2
City Code Table
City
Code
City
UTC
Differential
Other major cities in same time zone
PPG Pago Pago –11
HNL Honolulu –10 Papeete
ANC Anchorage –9 Nome
YVR Vancouver –8 Las Vegas, Seattle/Tacoma, Dawson City
SFO San Francisco
LAX Los Angeles
DEN Denver –7 El Paso, Edmonton
MEX Mexico City –6 Winnipeg, Houston, Dallas/Fort Worth, New Orleans
CHI Chicago
MIA Miami –5 Montreal, Detroit, Boston, Panama City, Havana,
Lima, Bogota
NYC New York
CCS Caracas –4 La Paz, Santiago, Port Of Spain
YYT St. Johns –3.5
RIO Rio De Janeiro –3 Sao Paulo, Buenos Aires, Brasilia, Montevideo
RAI Praia –1
L-1
City Code Table
Operation Guide 3583
L-5
City
Code
City
UTC
Differential
Other major cities in same time zone
GUM Guam +10 Melbourne, Rabaul
SYD Sydney
NOU Noumea +11 Port Vila
WLG Wellington +12 Christchurch, Nadi, Nauru Island
x Based on data as of June 2005.
x This table shows the city codes of this watch.
x The rules governing global times (UTC offset and GMT differential) and summer
time are determined by each individual country.
L-4
City
Code
City
UTC
Differential
Other major cities in same time zone
DXB Dubai +4 Abu Dhabi, Muscat
KBL Kabul +4.5
KHI Karachi +5
MLE Male
DEL Delhi +5.5 Mumbai, Kolkata
DAC Dhaka +6 Colombo
RGN Yangon +6.5
BKK Bangkok +7 Jakarta, Phnom Penh, Hanoi, Vientiane
SIN Singapore +8 Kuala Lumpur, Taipei, Manila, Perth, Ulaanbaatar
HKG Hong Kong
BJS Beijing
SEL Seoul +9 Pyongyang
TYO Tokyo
ADL Adelaide +9.5 Darwin
