Seiko GPS SOLAR ASTRON 5X53 User manual

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READ FIRST
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CONTENTS
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Complete User Guide
5X53 GPS Solar Watch (Dual Time)

Thank you very much for choosing a SEIKO watch.
For proper and safe use of your SEIKO watch,
please read carefully the instructions in this
booklet before using it.
Keep this manual handy for easy reference.
* Length adjustment service for metallic bands is available at the retailer from whom the watch
was purchased. If you cannot have your watch repaired by the retailer from whom the watch
was purchased because you received the watch as a gift, or you moved to a distant place,
please contact SEIKO CUSTOMER SERVICE CENTER. The service may also be available
on a chargeable basis at other retailers, however, some retailers may not undertake the
service.
* If your watch has a protective film for preventing scratches, make sure to peel it off before
using the watch. If the watch is used with the film on it, dirt, sweat, dust, or moisture may be
attached to the film and may cause rust.
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ASTRON 5X53 GPS SOLAR

Handling cautions
b WARNING
Please note that there is a risk of serious consequences such as severe injury if the following safety
regulations are not strictly observed.
Immediately stop wearing the watch in following cases:
○If the watch body or band becomes edged by corrosion etc.
○If the pins protrude from the band.
* Immediately consult the retailer from whom the watch was purchased or SEIKO CUSTOMER
SERVICE CENTER.
Keep the watch and accessories out of the reach of babies and
children.
Care should be taken to prevent a baby or a child accidentally swallowing the accessories.
If a baby or child swallows the battery or accessories, immediately consult a doctor, as it will be harmful
to the health of the baby or child.
Do not remove the secondary battery from the watch.
* About the secondary battery → Power Source P. 41
Replacement of the secondary battery requires professional knowledge and skill. Please ask the
retailer from whom the watch was purchased for replacement of the secondary battery.
Installation of an ordinary silver oxide battery can generate heat that can cause bursting and ignition.
b CAUTION
Please note that there is a risk of minor injury or material damage if the following safety regulations
are not strictly observed.
Avoid the following places for wearing or keeping the watch:
○Places where volatile agents (cosmetics such as polish remover, bug repellent, thinners etc.) are
vaporizing
○Places where the temperature drops below
5°C or rises above 35°C for a long time (41°F
and 95°F)
○Places affected by strong magnetism or static
electricity
○Places affected by strong vibrations
○Places of high humidity
○Dusty places
If you observe any allergic symptoms or skin irritation
Stop wearing the watch immediately and consult a specialist such as a dermatologist or an allergist.
Other cautions
○For adjusting the length of the metallic band, specialized knowledge and expertise are necessary.
Therefore, in such a case, contact the retailer from whom the watch was purchased. If you attempt to
adjust the metallic band, injury may occur to your hand or fingers, or parts of the band may be lost.
○Do not disassemble or tamper with the watch.
○Keep the watch out of the reach of babies and children. Extra care should be taken to avoid risks of
any injury or allergic rash or itching that may be caused when they touch the watch.
○When disposing of used batteries, follow the instructions of your local authorities.
○If your watch is of the fob or pendant type, the strap or chain attached to the watch may damage your
clothes, or injure the hand, neck, or other parts of your body.
○Please keep in mind that if a watch is taken off and placed down as it is, the case back, the band and
the clasp will rub against each other possibly causing scratches on the case back. We recommend
placing a soft cloth between the case back, the band and the clasp after taking off your watch.
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ASTRON 5X53 GPS SOLAR

b WARNING
Do not use the watch for scuba diving or saturation
diving.
The various tightened inspections under simulated harsh environment, which are
usually required for watches designed for scuba diving or saturation diving, have not
been conducted on the water resistant watch with the BAR (barometric pressure)
display. For diving, use watches specifically designed for diving.
b CAUTION
Do not pour running water directly from faucet.
The water pressure of tap water from a faucet is high enough to degrade the water
resistant performance of a water resistant watch for everyday life.
b CAUTION
Do not turn or pull out the crown when the watch is wet.
Water may get inside of the watch.
* If the inner surface of the glass is clouded with condensation or water droplets
appear inside of the watch for a long time, the water resistant performance of the
watch is deteriorated. Immediately consult the retailer from whom the watch was
purchased or SEIKO CUSTOMER SERVICE CENTER.
Do not leave moisture, sweat and dirt on the watch for
a long time.
Be aware of a risk that a water resistant watch may lessen its water resistant
performance because of deterioration of the adhesive on the glass or gasket, or the
development of rust on stainless steel.
Do not wear the watch while taking a bath or a sauna.
Steam, soap or some components of a hot spring may accelerate the deterioration
of water resistant performance of the watch.
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ASTRON 5X53 GPS SOLAR

This is a GPS solar watch.
* Unlike navigation equipment, this GPS solar watch is not designed to constantly receive GPS signals from GPS satellites without any operation.
This watch receives GPS signals only in the time zone adjustment mode, automatic or manual time adjustment mode.
This watch has the following features.
GPS signal reception
This watch can be set to the precise local time
by just one button operation anywhere in the
world.
DST (Daylight Saving Time) is reflected in the
time that appears.
This watch quickly adjusts the time by receiving GPS signals
from GPS satellites.
→ Place where GPS signals can be easily received/Place
where GPS signals cannot be received P. 16
This watch responds to all the time zones around the world.
→ Time zone P. 6
When the region or time zone where the watch is used is
changed, please carry out operation of “time zone adjustment.”
→ How to adjust the time zone P. 20
Solar charging Function
This watch operates by solar charging.
Expose the dial to light to charge the watch.
The watch will operate for about 6 months on a full charge.
When the energy stored in the watch runs out
completely, it takes time to fully charge the watch, so
please keep in mind to charge the watch regularly.
→ How to charge the watch P. 14
→ Standard Charging Time P. 14
Automatic time adjustment function
This watch automatically adjusts the time in
accordance with action patterns during use.
When the watch has sensed sufficient brightness under
an open sky, it automatically receives GPS signals from
GPS satellites. This function enables the watch to
automatically adjust the time precisely even while you are
using the watch.
→ Automatic time adjustment P. 29
* This watch is unable to receive GPS signals when
the energy stored in the watch is low.
→ Check the charging status P. 13
Features
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ASTRON 5X53 GPS SOLAR

Mechanism by which the GPS solar watch sets time and date
GPS satellite
This is a satellite operated by the United States Department of
Defense (official name is NAVSTAR), and orbits the earth at an
altitude of 20,000 km.
Initially, this was a military satellite, but at present, information
is partially disclosed to the public and used in various equipment
including car navigation systems and cellular phones.
The GPS satellite is mounted with a high-accuracy atomic clock
with an accuracy deviation of 1 second per 100,000 years.
Mechanism by which this watch sets the time and date
This watch receives GPS signals from GPS satellites to set the
time and date based on the following information.
•Precise time and date based on the atomic clock
•Information about a time zone where you are and its adoption
of DST (Daylight Saving Time)
(The current location is basically positioned by more than 4
GPS satellites, and which zone of the total of 39 time zones
around the world you are in, and details regarding its adoption
of DST (Daylight Saving Time), is identified.)
* To receive information about a time zone where you are, it is necessary
to adjust the time zone.
→ How to adjust the time zone P. 20
* Unlike navigation equipment, this GPS solar watch is not designed to
constantly receive GPS signals from GPS satellites without any
operation.
This watch receives GPS signals only in the time zone adjustment mode,
automatic or manual time adjustment mode.
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ASTRON 5X53 GPS SOLAR

Time zone
Based on Coordinated Universal Time (UTC), the standard time commonly used is adopted by countries and regions around the world.
Standard time is determined by nations and regions, with “time zone” used to refer to the whole of a region that uses the same standard time. At present, the globe is divided into 39 time zones (as of
March, 2018).
DST (Daylight Saving Time)
Depending on the area, DST (Daylight Saving Time) is individually set.
Daylight Saving Time means summer time, which is a system to lengthen daylight time by advancing 1 hour when daylight time is long in summer.
Daylight saving time has been adopted in about 80 countries, mainly in Europe and North America. The adoption and duration of daylight saving time vary depending on the country.
If the time zone adjustment is successful, data regarding the adoption of DST (Daylight Saving Time) for the country in which the GPS signals were received is reflected in the time that appears.
* DST (daylight saving time or “summer time”) in each region may be changed by countries and regions.
Coordinated Universal Time (UTC)
UTC is the universal standard time coordinated through an international agreement. This is used as the official time for recording time around the world. The time obtained by adding a leap second to
the “International Atomic Time (TAI)” determined based on the atomic clock around the world and coordinated in order to compensate for deviations from universal time (UT) which is astronomically
determined is the UTC.
Time zone
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ASTRON 5X53 GPS SOLAR

The following functions are included
When the region or time zone where the watch is used is changed
Adjust the time zone.
The watch displays the precise local time where you are (which includes DST (Daylight
Saving Time)).
→ Time zone adjustment P. 19
→ Time zone P. 6
→ Time zone display and list of time zones around the world P. 12
Los Angeles
7:00 PM on 6th London
3:00 AM on 7th
To set only the time
The watch displays the precise time of the time zone that is set by operation of “manual
time adjustment.”
→ How to manually adjust the time P. 22
→ Check the time zone and DST (Daylight Saving Time) settings P. 25
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ASTRON 5X53 GPS SOLAR

How to check when the time zone information was configured for your watch
The case back shows the caliber-case number of
your watch.
The number to identify
the watch type
Caliber/case
number
* Display may vary depending on the model.
By referring to caliber-case number shown on the case back, you will be able to determine when
the time zone data was configured.
For more details, refer to the URL below.
https://www.seikowatches.com/global-en/customerservice/knowledge/
gpstimezonedatainfo
If the official time zone, etc., has changed in a region after the watch’s time zone data or DST
(Daylight Saving Time) data was configured, the correct time will not be displayed even after
receiving GPS signals. Please perform the following operations to display the correct time:
<To set the time of this watch in a region where the official time zone or DST
(Daylight Saving Time) has changed>
1. Select the time zone appropriate for the current time in the target region by manual time zone
setting and do settings for DST (Daylight Saving Time), as necessary.
For details, please refer to "Turn ON DST (Daylight Saving Time)" P. 24.
2. Next, adjust the time by manual time adjustment.
For details, please refer to "Manual time adjustment" P. 21.
3. When using the watch within the same time zone, the correct time will be displayed after
automatic (GPS) or manual time adjustments.
4. When moving from a region where the official time zone has changed to a different time zone,
then back to the region where the official time zone has changed, carry out the same operations
from 1. - 3. as indicated above to display the correct time in the region where the official time
zone has changed.
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ASTRON 5X53 GPS SOLAR

CONTENTS
1. READ FIRST .................................................................................................................. 2
Handling cautions ........................................................................................................... 2
Features ......................................................................................................................... 4
Mechanism by which the GPS solar watch sets time and date ....................................... 5
Time zone ....................................................................................................................... 6
The following functions are included .............................................................................. 7
How to check when the time zone information was configured for your watch ............... 8
2. CONTENTS .................................................................................................................... 9
3. BEFORE USE .............................................................................................................. 10
Names of the parts ....................................................................................................... 10
Indicator hand display and reception result display ...................................................... 11
Time zone display and list of time zones around the world ........................................... 12
Check the charging status ............................................................................................ 13
About charging ............................................................................................................. 14
4. BASIC OPERATION (HOW TO SET THE TIME/HOW TO RECEIVE GPS
SIGNALS, ETC.) ................................................................................................................. 15
Basic operation flow ..................................................................................................... 15
GPS signal reception .................................................................................................... 16
To adjust the time zone and time by GPS signal reception (time zone adjustment) ...... 19
To adjust only the time by GPS signal reception (manual time adjustment) ................. 21
To set the watch to the local time of the destination in an airplane, etc.
(Manual time zone setting) ........................................................................................... 23
Set DST (Daylight Saving Time) ................................................................................... 24
To adjust time on sub-dial ............................................................................................ 26
Switching between the main-dial and sub-dial (Time Transfer Function) ...................... 28
Automatic time adjustment ........................................................................................... 29
When boarding (in-flight mode ( )) ........................................................................... 30
Leap second (Automatic leap second reception function) ............................................ 31
5. IN CASE OF AN UNUSUAL MOVEMENT OF THE SECONDS HAND .... 33
Seconds hand movement and watch state (energy depletion forewarning function) .... 33
6. TO PRESERVE THE QUALITY OF YOUR WATCH ........................................ 34
Daily care ..................................................................................................................... 34
Performance and caliber / case number ....................................................................... 34
Water resistant performance ........................................................................................ 34
Magnetic resistance ..................................................................................................... 35
Band ............................................................................................................................. 36
How to use an easy adjust type clasp ........................................................................... 37
How to use an adjustable three-fold clasp .................................................................... 38
How to use an adjustable three-fold clasp (Pointed tip diving type) .............................. 39
Lumibrite ...................................................................................................................... 40
Power Source ............................................................................................................... 41
After sales service ........................................................................................................ 42
7. TROUBLESHOOTING .............................................................................................. 43
When the watch is unable to receive GPS signals ........................................................ 43
Adjust the time under a condition in which the watch is unable to receive GPS signals
(Manual time setting) .................................................................................................... 43
When the sub-dial, day hand, date, indicator hand or hour/minute/seconds hand
position is misaligned ................................................................................................. 45
Troubleshooting ........................................................................................................... 49
8. FUNCTION LIST/SPECIFICATIONS ................................................................... 53
Index ............................................................................................................................ 53
SPECIFICATIONS ........................................................................................................ 54
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2CONTENTS
ASTRON 5X53 GPS SOLAR

Names of the parts
1
6
7
8
9
0
a
2
3
5
4
* The orientation and design of the display may vary depending on the model.
1Hour hand
2Indicator hand
3Seconds hand
4Sub-dial (12-hour system)
5Minute hand
6Button A
7Day hand (day of the week)
8Crown
9Date
0Button B
aSub-dial AM/PM hand
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3BEFORE USE
ASTRON 5X53 GPS SOLAR

1
25
6
3
4
* The orientation and design of the display may vary depending on the
model.
1Display of reception result
Y: Reception successful (8-second position)
N : Reception failed (52-second position)
→ Check the reception result P. 18
2Display of receiving process
Receiving
process 1 (time adjustment) 4+ (time zone adjustment)
Display
→ Check the reception result P. 18
→ Time zone adjustment P. 19
→ Manual time adjustment P. 21
→ Automatic time adjustment P. 29
3Display of in-flight mode ( )
Hand position In-flight mode ( ) status
Display
→ In-flight mode P. 30
4Display of charging status
Hand
position full middle low
Display
→ Check the charging status P. 13
→ How to charge the watch P. 14
5Display of leap second data receipt
Hand position Receiving leap second data
Display
→ Receiving leap second data P. 31
6Display of DST (Daylight Saving Time)
Hand
position
AUTO
(automatic) ST (OFF) DST (ON)
Display
→ Check the time zone and DST (Daylight Saving Time)
settings P. 25
→ Set DST (Daylight Saving Time) P. 24
Indicator hand display and reception result display
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3BEFORE USE
ASTRON 5X53 GPS SOLAR

The following list shows the relationship between displays of the bezel and dial ring and time difference from the UTC.
Please refer to the seconds hand positions below to set the time zone or to check the time zone setting.
DST (Daylight Saving Time) has been adopted in countries marked with a H.
In the Lord Howe Island time zone in Australia with a I mark, the time is advanced by 30 minutes while DST (Daylight Saving Time) is in effect. This watch corresponds to DST in the Lord Howe Island
time zone.
Display of time zone
Representative city names…
28 cities among the total of 39 time zones around the world
Time difference…
+14 hours ~ –12 hours
→ Check the time zone and DST (Daylight Saving Time) settings P. 25
→ Time zone adjustment P. 19
Display of time difference
* The displays of city code and the time difference from UTC are Subject
to change depending on model.
* “·” between figures of the display of time difference shows that there is a
time zone in that place.
City code
Display of time
difference City name UTC ± hours
LON UTC HLondon 0
PAR 1 HParis/ HBerlin +1
CAI 2 Cairo +2
JED 3 Jeddah +3
· · HTehran +3.5
DXB 4 Dubai +4
· · Kabul +4.5
KHI 5 Karachi +5
DEL ·Delhi +5.5
· · Kathmandu +5.75
DAC 6 Dhaka +6
· · Yangon +6.5
BKK 7 Bangkok +7
BJS 8 Beijing +8
· · PyongYang +8.5
· · Eucla +8.75
TYO 9 Tokyo +9
ADL ·HAdelaide +9.5
SYD 10 HSydney +10
· · ILord Howe Island +10.5
City code
Display of time
difference City name UTC ± hours
NOU 11 Nouméa +11
WLG 12 HWellington +12
· · HChatham Islands +12.75
TBU 13 Nuku’alofa +13
CXI 14 Kiritimati +14
·-12 Baker Island -12
MDY -11 Midway islands -11
HNL -10 Honolulu -10
· · Marquesas Islands -9.5
ANC -9 HAnchorage -9
LAX -8 HLos Angeles -8
DEN -7 HDenver -7
CHI -6 HChicago -6
NYC -5 HNew York -5
SDQ -4 Santo Domingo -4
· · HSt. John’s -3.5
RIO -3 HRio de Janeiro -3
FEN -2 Fernando de Noronha -2
PDL -1 HAzores -1
* The time zone and adoption of DST (Daylight Saving Time) for each
region are current as of March, 2018.
Time zone display and list of time zones around the world
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3BEFORE USE
ASTRON 5X53 GPS SOLAR

The indicator hand position shows whether this watch is able or unable to receive GPS signals.
In addition, for the low charging state, the movement of the seconds hand shows the energy depletion state in further detail.
* GPS signal reception requires a lot of energy. Keep in mind to regularly charge the watch by expose to light.→ About charging P. 14
Check the charging status
Reception is allowed
Indicator display Charging status Solution
full
Reception is allowed.
Use the watch as it is.
→ P. 15
middle
Reception is allowed, but keep in mind to charge
the watch.
→ P. 15
Reception is not allowed
Indicator display Movement of
seconds hand Charging status Solution
1-second
interval
movement
low
The watch is unable
to receive GPS
signals, but has
energy to operate.
Charge the watch at least until the
indicator hand points to the level
position so that the watch is able to
receive GPS signals.
→ About charging P. 14
2-second
interval
movement
-
The watch is unable
to receive GPS
signals, and does not
have energy to
operate. (The energy
depletion
forewarning function
is activated. → P. 33)
Continue to charge the watch at least
until the indicator hand points to the
level position so that the watch is able
to continuously operate and receive
GPS signals.
→ About charging P. 14
5-second
interval
movement
-
The charging status is not
displayed for the in-flight mode
( ).
Reset the in-flight mode ( ) as long
as possible.
→ Reset the in-flight mode
(). P. 30
When the indicator hand points to
“low,” charge the watch following the
above.
→ About charging P. 14
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3BEFORE USE
ASTRON 5X53 GPS SOLAR

About charging
How to charge the watch
Expose the dial to light to charge the watch.
To ensure optimal performance of the watch,
make sure that the watch is kept sufficiently
charged at all times.
Under the following situations, the energy of
the watch is likely to be depleted, resulting in
stoppage of the watch:
•The watch is concealed under a sleeve.
•The watch is used or stored under
conditions where it cannot be exposed to
light for a long time.
* When charging the watch, make sure that the watch is not heated to a high temperature. (The operational
temperature range is between -10°C to +60°C (14 ºF and 140 ºF).)
* When first using the watch or starting to use the watch after it has stopped because of the energy depletion,
sufficiently charge the watch referring to the table on the page at the right.
Standard Charging Time
Charge the watch using the times below as a guide.
GPS signal reception consumes a lot of energy. It is necessary to charge the watch by exposing it
to light so that the indicator hand points to the “middle” or “full” position. (If the charging status is
displayed as “low,” the reception will not start even with manual GPS signal reception.)
→ Check the charging status P. 13
Illumination
lx (LUX) Light source Condition (Example)
From the state where the watch is
stopped (not charged)
In the state
where the
hand moves
(the watch is
charged)
To fully
charged
To one-second
interval movement
is secured
To move for
one day
700 Fluorescent
light General offices - - 3.5 hours
3,000 Fluorescent
light 30 W 20 cm 420 hours 12 hours 1 hour
10,000
Sunlight
Fluorescent
light
Cloudy day
30 W 5 cm 115 hours 4 hours 15 minutes
100,000 Sunlight
Sunny day (Under the
direct sunlight on a
summer day)
50 hours 1.5 hours 10 minutes
The figures of “Time required for charging the watch to start moving at one-second intervals” are
estimations of time required to charge the stopped watch by exposing it to light until it moves at
steady one-second intervals. Even if the watch is partially charged for a shorter period, the watch
will resume one-second- interval movement. However, it may shortly return to two-second-interval
movement. Use the charging time in this column as a rough guide for sufficient charging time.
* The required charging time slightly varies depending on the model.
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3BEFORE USE
ASTRON 5X53 GPS SOLAR

•When the region or
time zone where
the watch is used
is changed
•To set only the
time
1. Check the place where GPS signals can be
easily received
→ Place where GPS signals can be easily received/Place
where GPS signals cannot be received P. 16
Place where GPS signals can be
easily received
Outdoors under an open sky with good
visibility
Place where GPS signals cannot be
received
Example: Within a subway station
2. Set the time zone and set the time and date
< Setting by GPS signal reception >
Receive GPS signals, set the
time zone and set the time
and date
* The time includes DST
(Daylight Saving Time) due to
the time zone adjustment.
→ How to adjust the time
zone P. 20
Set only the time → How to manually adjust the
time P. 22
< Manual setting >
→ Check the time zone and DST
(Daylight Saving Time) settings
P. 25
Time zone setting is not correct → How to manually set the time zone
P. 23
Time zone setting is correct → How to manually set the time P. 44
Basic operation flow
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4
BASIC OPERATION (HOW TO SET THE TIME/HOW TO RECEIVE GPS SIGNALS, ETC.)
ASTRON 5X53 GPS SOLAR

Place where GPS signals can be easily received/Place where GPS signals cannot be received
Easy to receive
•Outdoors under an open sky with good visibility
Difficult to receive
•The smaller the sky, the more difficult it is to receive
GPS signals. In addition, it will also be difficult to
receive GPS signals, if there is something that
obstructs the GPS signals during reception (in
particular, during time zone adjustment).
Examples:
•Between tall buildings
•Near wooded area
•Station/Airport
•Indoors with windows
* GPS signals cannot be received depending on window glass
type.
Refer to the “ Cannot receive.”
Cannot receive
•The sky cannot be seen or only part of the sky can be
seen.
•There is something hindering the reception.
Examples:
•Indoors without windows
•Underground
•During passage of a tunnel
•Through special glass with thermal emission shield
effect, etc.
•Close to equipment generating noise or performing
wireless communications
GPS signal reception
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4
BASIC OPERATION (HOW TO SET THE TIME/HOW TO RECEIVE GPS SIGNALS, ETC.)
ASTRON 5X53 GPS SOLAR

List of GPS signal reception methods (characteristics of all three types)
Reception
method Time adjustment Time zone adjustment Leap second data reception
Display
How to
manually
adjust the time
→ P. 21
Automatic time
adjustment
→ P. 29
How to adjust the
time zone
→ P. 19
Features
Time adjustment
Precise current time of the set time
zone is displayed
Time zone identification and
time adjustment
Time zone where you are is identified,
and the precise current time, reflecting
the addition conditions of DST (Daylight
Saving Time), is displayed
Leap second
reception
Ready for leap second
data reception and
receiving Leap second
data → P. 31
Number of
acquired
satellites
necessary for
reception
One unit (to obtain only time
information)
Basically more than 4 units (to obtain time
information and time zone information) -
Time taken for
reception 3 seconds to 1 minute 30 seconds to 2 minutes 30 seconds to
18 minutes
What kind of
situation
To set the watch to the precise time
while it is used in the same time
zone
When the watch is used in a different time
zone
This is performed
automatically after
GPS signal reception
(automatic time
adjustment, manual
time adjustment, or
time zone adjustment)
on or after June 1st
and December 1st.
GPS signal reception Q & A
Q : When the watch is moved to a different time zone, does the watch automatically display the
local time?
A : The watch does not automatically display the local time just by changing location.
If you are in a place where GPS signals can be easily received, adjust the time zone. The
watch automatically displays the local time.
When you are in a place where GPS signals cannot be received, manually set the time zone.
→ Manual time zone setting P. 23
The watch can be set to all time zones around the world.
Q : Is DST (Daylight Saving Time) automatically changed by receiving GPS signals?
A : The settings for DST (Daylight Saving Time) are done automatically by doing a time zone
adjustment.
The time automatically switches to adjust for the adoption and duration of DST (Daylight
Saving Time) for regions that follow DST (Daylight Saving Time).
“Normal time” always appears for regions that do not adopt DST (Daylight Saving Time).
Manually switch the DST (Daylight Saving Time) setting if you have moved to a place that
adopts different DST (Daylight Saving Time) details, even if the area is the same time zone.
→ Set DST (Daylight Saving Time) P. 24
Even in the same time zone, some countries and regions do not adopt DST (Daylight Saving
Time).
→ Time zone display and list of time zones around the world P. 12
Q : Is it necessary to carry out special operation for years in which a leap second is added?
A: No special operation is necessary.
Since the watch receives leap second data at the same time of receiving GPS signals
(automatic time adjustment, manual time adjustment, or time zone adjustment) on or after
June 1st and December 1st, a leap second is automatically added by periodically receiving
GPS signals. For details, refer to "Leap second (Automatic leap second reception
function)" P. 31.
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BASIC OPERATION (HOW TO SET THE TIME/HOW TO RECEIVE GPS SIGNALS, ETC.)
ASTRON 5X53 GPS SOLAR

Check that reception was successful (reception result display)
The type of reception and reception result (success or failure) of the last GPS signal reception is displayed for 5 seconds.
1
Press Button A once and then
release it
The seconds hand and indicator hand display the
reception result.
Press
and then
release
* When Button A is kept pressed, the watch enters the
Manual time adjustment operation.
The seconds hand displays the result of the GPS signal
reception (time adjustment or time zone adjustment).
The indicator hand points to “1” or “4+” which shows
“time adjustment” or “time zone adjustment.”
Seconds hand
Indicator hand
Seconds hand: Reception result (success/failure)
Result Successful Failed
Display
Position Y 8-second position N 52-second
position
Indicator hand:
Reception method (time adjustment or time zone
adjustment)
Type 1 (Time
adjustment)
4+ (Time zone
adjustment)
Display
* The indicator hand points to “4+” as a result of time
zone adjustment.
* After 5 seconds have elapsed or when Button B is
pressed, the watch returns to the time display mode.
When the reception result is Y
•The reception was successful.
Use the watch as it is.
When the reception result is N
•Move to the outdoors where GPS
signals can be easily received as
necessary to receive GPS signals.
→ Place where GPS signals can be easily
received/Place where GPS signals cannot
be received P. 16
* When approximately four days have elapsed after
successful reception, the reception result display
becomes “N”.
* Even under a state where GPS signal cannot be
received, the watch operates with quartz accuracy
(at loss/gain ±15 seconds per month).
When the reception has failed in any way,
manually set the time and date.
→ How to manually set the time P. 44
2
The result of the reception is displayed
18
4
BASIC OPERATION (HOW TO SET THE TIME/HOW TO RECEIVE GPS SIGNALS, ETC.)
ASTRON 5X53 GPS SOLAR

Time zone adjustment
The time zone where you are is localized to adjust the watch to the precise
current time by just one button operation anywhere in the world.
This reflects the data regarding the adoption of DST (Daylight Saving Time) in
the country that received the GPS signals.
The time automatically switches to adjust for the adoption and duration of DST
(Daylight Saving Time) for countries that follow DST (Daylight Saving Time).
“Normal time” always appears for countries that do not adopt DST (Daylight
Saving Time).
→ How to adjust the time zone P. 20
* Failure or success of reception depends on the reception environment. → Place where GPS signals can be easily
received/Place where GPS signals cannot be received P. 16
* GPS signal reception consumes a lot of energy.
Keep in mind to regularly charge the watch by expose to light so that the indicator hand points to the “middle” or
“full.”→ How to charge the watch P. 14
If the charging status is displayed as “low,” the reception will not start even with operation of GPS signal reception.
→ Check the charging status P. 13
Precautions on time zone adjustment
If the time zone is adjusted near a time zone boundary, the time of the adjacent time zone
may be displayed.
In some areas the boundaries observed by the watch may not exactly correlate to the actual
time zone markers on the land. This does not indicate a malfunction.
In this case, set the time zone in the manual time zone setting mode.
→ How to manually set the time zone P. 23
When the time zone is adjusted while traveling on land, avoid time zone boundaries to carry
out time zone adjustment in the representative cities in the time zone whenever possible.
In addition, when the watch is used near time zone boundaries, make sure to check the
time zone setting, and manually set the time zone as necessary.
To adjust the time zone and time by GPS signal reception (time zone adjustment)
19
4
BASIC OPERATION (HOW TO SET THE TIME/HOW TO RECEIVE GPS SIGNALS, ETC.)
ASTRON 5X53 GPS SOLAR