Time Zones And Time Differences; Time Difference Adjustment Q&A; Charging The Battery; How To Charge The Battery - Seiko 7B72 How To Use Manual

■ Time zones and time differences

There are time differences around the world based on "Coordinated Universal Time (UTC)."
There are 24 regions (Time Zones) around the world with a time difference of one hour. This
system has been adopted internationally by setting the total time difference around the world as
24 hours.
Further, Daylight Saving Time (DST) is individually adopted in countries and regions.
[What is UTC (Coordinated Universal Time)?]
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UTC is the universal standard time coordinated through international agreement. It is used as the official
time around the world. UTC is a time coordinated by adding leap seconds to the "International Atomic
Time (TAI)" determined from atomic clocks in the world, in order to correct the deviation from the
astronomically defined universal time (UT).
[What is summer time (DST)?]
Summer time is Daylight Saving Time (DST).
Advance the watch one hour to prolong daytime during longer daylight hours 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 (DST) vary depending on the country.
* Time differences between regions and daylight saving time may change due to circumstances of a country or
region.
* In some regions, time zones that differ from UTC by half- or quarter-hour time differences are established. (For
example, some parts of India)
* Each indication may differ depending on the model (design) of the watch.
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Charging the battery

■ How to charge the battery

Expose the dial to light to charge the watch.
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To ensure optimal performance of the watch, make
sure that the watch is kept sufficiently charged at all
times.
* Be careful to make sure that the watch does not get hot when it is charging. (The operating temperature range is
-10°C to +60°C.)
* When you first start using the watch or starting it after it stopped due to a lack of charge, charge the watch sufficiently
using the table on P.35 as a guide.
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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.
■ Time difference adjustment Q&A
Q : When returning to Japan from overseas, is the time automatically set to Japan time?
A : Just moving does not adjust your watch to Japanese local time.
When wearing a watch in Japan, set to Japan time by use of the time difference adjustment function.
Q : The hands stop during operation of time difference setting, therefore, does time lag occur?
A : The internal circuit stores the time, therefore, no time lag occurs.
Q : When a time difference for regions out of the radio signal reception range is set, the watch will not
receive a radio signal. How is the accuracy of the watch at that time?
A : The watch has an accuracy of a normal quartz watch in that case. (Monthly rate: ±15 seconds)
Q : How is adjustment made to a local time with a time difference of 15 minutes or 30 minutes?
A : The time can be adjusted on a 1 hour basis by use of the time difference adjustment function. When
adjusting to a local time with a time difference of 15 minutes or 30 minutes, refer to "How to manually
set the time" → P.59

■ Guide to charging times

Charge the watch using the times below as a guide.
Illuminance
Light source Condition (Example)
lx (LUX)
Fluorescent
700 General offices
light
Fluorescent
3,000 30 W 20 cm
light
Fluorescent
30 W 5 cm
light
10,000
Sunlight Cloudy day
Sunny day (Under the
100,000 Sunlight direct sunlight on a
summer day)
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 seconds hand movement indicates the remaining amount of energy. "Checking the Charging Status" → P.14
* The required charging time slightly varies depending on the model of the watch.
In the state where
From the state where the watch is
the hand moves (The
stopped (Not charged)
watch is charged)
Time required for
Time required for charging the watch Time required for
fully charging the to start moving at charging the watch
watch one-second to last for 1 day
intervals
- - 4 hours
230 hours 6 hours
60 hours 1.5 hours 15 minutes
30 hours 30 minutes 3 minutes
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5
1 hour
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