Citizen F158 User manual

To check the movement number
A case number—4 alphanumeric characters and 6 or
more alphanumeric characters—is engraved on the
case back. (Figure on the right)
The first 4 characters of the case number represent
the movement number of the watch. In the example
on the right, “ ” is the movement number.
Thank you for your purchase of this Citizen watch.
Before using the watch, read this instruction manual carefully to ensure
correct use.
After reading the manual, store it in a safe place for future reference.
Be sure to visit the Citizen website at http://www.citizenwatch-global.com/ .
Here you will find a variety of information such as electronic setting guides,
answers to frequently asked questions, Eco-Drive recharging information and
more.
Engraving position example
The engraving position may
differ depending on watch
model.
1

Safety precautions — IMPORTANT
This manual contains instructions that should be strictly followed at all times
not only for optimal use, but to prevent any injuries to yourself, other persons or
property. We encourage you to read the entire booklet (especially, pages
86 -
99 ) and understand the meaning of the following symbols:
■ Safety advisories are categorized and depicted in this manual as follows:
DANGER
Highly likely to cause death or serious injury
WARNING
Can cause serious injury or death
CAUTION
Can or will cause minor or moderate injury or damage
2

■ Important instructions are categorized and depicted in this manual as follows:
(Following symbols are examples of Pictograms.)
Warning (caution) symbol followed by prohibited matters.
Warning (caution) symbol followed by instructions that should be
followed or precautions that should be observed.
3
Safety precautions — IMPORTANT

4
Precautions to be taken when diving
PROHIBITED Do not use this watch while diving when...
• Do not use your watch while diving when the watch stops or exhibits any abnormal operation.
CAUTION Diving with the watch
• Persons using the diver’s watch are strongly recommended to receive proper instruction and
training pertaining to diving and observe those rules at all times.
• Please use this watch properly only after you fully understand the operating procedures and
cautions.
Using this watch other than as indicated in this instruction manual may result in failure of the
watch to function properly.
• Check the water-resistant indications on the watch face or the case back. Never dive beyond
the indicated depth.
CAUTION Before diving
• Check items below before diving
-Check to see if the watch is sufficiently charged and the insufficient charge warning
(2-second interval movement) is not activated.
-Make sure that the watch is running correctly (check the movements of the time/calendar/
second hand)
-Check to see if the crown is properly pushed in and the screw down push button is securely
locked.

5
Precautions to be taken when diving
-Make sure that the band is firmly anchored to the watch body.
-Make sure that there are no cracks or other damage to the watch band or the glass face.
-Make sure that the register ring rotates properly.
CAUTION During diving
• Do not push any push buttons or pull out the crown in the water. Operating any of them in
water may cause trouble including deterioration of water resistance.
• Be careful not to hit the watch against hard objects such as equipment or rocks.
CAUTION After diving
• Check to see if the crown is pushed in and the screw down push button is locked before
removing the sea water, dirt, and sand attached to the watch with fresh water. Then, wipe the
fresh water.

6
Features
 Satellite Wave-GPS
Receives location and time information sent from GPS
satellites and adjusts the time and calendar on the watch
automatically.
 200 m water resistant watch for diving
This watch has 200 m water resistance and can be used for
air diving with an air tank (SCUBA diving). (You cannot use
it for saturation diving using helium gas.)
It conforms with the standard of ISO 6425: 2018.
 Diving mode
It prevents wrong operation of the watch during diving; it also halts some
functions such as satellite signal reception to keep the current time indicated.
 Eco-Drive
No periodical battery replacement is needed. This watch is fueled by light.

7
Features
 Light-Level Indicator
Indicates current power generation amount.
It can be used as a reference for choosing a good charging place.
 World time
Indicates the time around the world by choosing one of 38 time zones.
 ±5-second average monthly accuracy
Keeps high accuracy without time signal reception.
 Perpetual calendar
No need for monthly and leap-year date correction until February 28, 2100.
* “Eco-Drive” is an original technology of Citizen.

8
CONTENTS
Precautions to be taken when diving ................
4
Before using this watch...........................
12
Band adjustment........................................
13
Protective stickers.......................................
13
How to use a specially designed crown/button...........
14
Component identification.........................
16
Checking the power reserve and power generation
amount .......................................
18
Checking the reception result of the satellite signal...
24

9
CONTENTS
Setting the world time ...........................
26
Checking the current time zone setting ..................
27
Obtaining location information from satellite signals .....
34
Setting the time zone manually. . . . . . . . . . . . . . . . . . . . . . . . . .
36
Receiving time information .......................
37
Switching summer time (DST) and standard time.....
44
Using the diving mode ...........................
46
Charging your watch .............................
48
Continued on the next page

10
CONTENTS
Information on satellite signal reception ............
54
Checking and adjusting the leap second setting .........
59
Checking and adjusting the rollover number setting .....
62
Adjusting the time and calendar manually ..........
66
Using the rotating bezel ..........................
72
Troubleshooting .................................
74
Checking and correcting the reference position..........
74
Symptom and remedies.................................
78