Citizen 901 User manual

1
English
To determine the movement number
Your watch features a case number engraved on the
case back (refer to figure to the right).
The first four characters of the case number represent
the movement caliber number of the watch.
In the example on the right, “1234” 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, be sure to store this manual in a safe place should it be needed
for future reference.
Engraving position example
The engraving position may differ
depending on watch model.

2
Safety precautions
This manual may contain certain safety advisories. Your watch should be used in
accordance with these advisories at all times to ensure optimal enjoyment of your watch
and to prevent injury to yourself, other persons and/or damage to property.
■ Safety advisories are categorized and depicted in this manual as follows:
WARNING May cause serious injury or death
CAUTION May or will cause minor or moderate injury or damage
■ Important instructions are categorized and depicted in this manual as follows:
Warning (caution) symbol followed by instructions that should be
followed and/or precautions that should be observed.

3
English
Table of contents
Setting the time and date.................................................................. 4
Mainspring ........................................................................................... 6
Mechanical watches............................................................................ 8
Water resistance ................................................................................ 10
Precautions and usage limitations ................................................ 13
Maintenance ...................................................................................... 21
Specifications..................................................................................... 22

4
Date
Crown
Setting the time and date
• When the screw down crown is equipped on your model, loosen the screw before
operation. After operation, return the crown to the normal position and tighten it.
• When the watch stops, turn the crown to the right (clockwise) in position 0to wind
the mainspring manually.
• The illustrations in this instruction manual may differ from the actual watch.
Hour hand
Minute hand
Second hand

5
English
While the hands indicate between 8:00 PM and 2:00 AM:
Do not perform steps 1and 2; otherwise, the date may not change properly.
If you want to perform the steps, first turn the crown in position 2to move the hands
so they are not indicating between 8:00 PM and 2:00 AM.
1. Pull out the crown to position 1.
2. Turn the crown to the right (clockwise) to set the date to one day before the date you
want to set.
3. Pull out the crown to position 2.
4. Turn the crown to the right (clockwise) to set the date.
• The watch indicates morning when the date changes.
5. Turn the crown to set the time.
• To set an afternoon or evening hour, turn the hands to 12:00 first, then set the time.
6. Push in the crown to position 0.
• The date is based on a 31-day calendar. Adjust the date on the 1st day after months
which have 28/29/30 days.

6
Mainspring
This watch runs using the power of the mainspring.
• Once the mainspring is wound fully, it will run for about 42 hours.
• Sufficient winding ensures stable and accurate movement.
About winding the mainspring
This watch is an automatic mechanical watch. (You can also wind the mainspring
manually.)
The mainspring is wound by swinging your arm. It is recommended to wear the watch
for more than 8 hours a day.
If you do not move your arms much in your daily life, for example you spend a lot of
time sat at a desk, the mainspring may not be wound sufficiently. In such cases, wind the
mainspring manually (see page 7).

7
English
Winding the mainspring manually
Turn the crown to the right (clockwise) in position 0.
Crown
• When the watch stops, turning the crown about 40 times will wind the mainspring
fully.
• When the mainspring is wound fully, turning the crown further does not damage the
mainspring.

8
Mechanical watches
About accuracy
The accuracy of mechanical watches in this instruction manual is static accuracy at
normal temperatures (between +5˚C and +35˚C).
The accuracy on the specifications may not be kept depending on the following
conditions of use:
• times the mainspring is wound
• position
• usage environment (temperature, magnetism, impact, etc.)
Times the mainspring is wound
Full winding of the mainspring ensures the most stable and accurate movement of
mechanical watches.
Position
When you wear the watch on the wrist, the position of the watch changes frequently,
and the movement of the watch is influenced by changes in the direction of gravity. This
affects accuracy of mechanical watches.

9
English
Usage environment (temperature, magnetism, impact, etc.)
• Because mechanical watches use metal in parts for keeping accuracy, changes in
temperature, which cause metal to expand and contract, will affect the accuracy of the
watch.
• Because mechanical watches use metal parts, exposure to magnetic fields affects
their accuracy. In order to keep the watch accurate, do NOT subject it to strongly-
magnetized objects.
• Strong shocks also affect the accuracy.
Maintenance
Mechanical watches may become inaccurate due to insufficient lubrication or wear.
Have the watch disassembled and cleaned (overhaul) every 2-3 years (charge basis).
It may be difficult to restore the watch from degradation after long-term use to its initial
performance even after repairs.

10
Name
Indication
Specification
Dial or Case back
Non-water resistant Non-water resistant
Everyday-use water resistant
watch WATER RESIST(ANT) Water-resistant to 3 atmospheres
Upgraded everyday use water-
resistant watch
WATER RESIST(ANT)
5 bar Water-resistant to 5 atmospheres
WATER RESIST(ANT)
10/20 bar
Water-resistant to 10 or 20
atmospheres
Water resistance
WARNING Water Resistance
• Refer to the watch dial and the case back for the indication of the water resistance of your watch. The
following chart provides examples of use for reference to ensure that your watch is used properly.
(The unit “1bar” is roughly equal to 1 atmosphere.)
• WATER RESIST(ANT) ××bar may also be indicated as W.R.××bar.