Since
radio
signals
can cross
multiple
time zones
and the
international
date line,
some
worldwide
standard
for time
and date
is needed.
This
standard
is Coordinated
Universal
Time,
abbreviated
UTC.
This was
formerly
known as Greenwich
mean time
(GMT).
Other
terms used
to refer
to it
include
"Zulu
time"
(after the
"Z"
often used
after UTC
times),
"universal
time,"
and
"world
time."
UTC is
used by
international
short-wave
broadcasters
in their
broadcast
and
program
schedules.
Ham radio
operators,
short-wave
listeners,
the
military,
and
utility
radio
services
are also
big users
of UTC.
Greenwich
mean time
was based
upon the
time at
the zero
degree
meridian
that
crossed
through
Greenwich,
England.
GMT became
a world
time and
date
standard
because it
was used
by
Britain's
Royal Navy
and
merchant
fleet
during the
nineteenth
century.
Today, UTC
uses
precise
atomic
clocks,
short-wave
time
signals,
and
satellites
to ensure
that UTC
remains a
reliable,
accurate
standard
for
scientific
and
navigational
purposes.
Despite
the
improvements
in
accuracy,
however,
the same
principles
used in
GMT have
been
carried
over into
UTC.
UTC
uses a
24-hour
system of
time
notation.
"1:00
a.m."
in UTC is
expressed
as 0100,
pronounced
"zero
one
hundred."
Fifteen
minutes
after 0100
is
expressed
as 0115;
thirty-eight
minutes
after 0100
is 0138
(usually
pronounced
"zero
one
thirty-eight").
The time
one minute
after 0159
is 0200.
The time
one minute
after 1259
is 1300
(pronounced
"thirteen
hundred").
This
continues
until
2359. One
minute
later is
0000
("zero
hundred"),
and the
start of a
new UTC
day.
To
convert
UTC to
local
time, you
have to
add or
subtract
hours from
it. For
persons
west of
the zero
meridian
to the
international
date line,
hours are
subtracted
from UTC
to convert
to local
time.
Use
this Java
Calculator
to get UTC
to Your LT
Zones
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