ISO
8601:2000(E)
2
©
ISO
2000
All
rights
reserved
ISO/IEC
646:1991,
Information
technology
-
ISO
7-bit
coded
character
set
for
information
interchange
.
ITU-R
RecommendationTF.460-5,
Standard-frequency
and
time-signal
emissions
.
ITU-R
RecommendationTF.686,
Glossary
.
3
Terms
and
definitions
For
the
purposes
of
this
International
Standard,
the
following
terms
and
definitions
apply.
3.1
Coordinated
Universal
Time
(UTC)
time
scale
maintained
by
the
Bureau
international
des
poids
et
mesures
(International
Bureau
of
Weights
and
Measures)
and
the
International
Earth
Rotation
Service
(IERS)
which
forms
the
basis
of
a
coordinated
dissemination
of
standard
frequencies
and
time
signals
NOTE
1
The
source
of
this
definition
is
ITU-R
Recommendation
TF.686
of
the
International
Telecommunication
Union
Radio.
ITU-R
has
also
defined
the
acronym
for
Coordinated
Universal
Time
as
UTC
(see
also
5.3.3).
NOTE
2
UTC
is
often
(incorrectly)
referred
to
as
Greenwich
Mean
Time.
NOTE
3
Additional
information
can
be
found
as
follows:
the
URL
for
the
ITU
http://www.itu.int/itudoc/itu-r/rec/tf/index.html
the
URL
for
the
International
Bureau
of
Weights
and
Measures
http://www.bipm.fr
the
URL
for
the
International
Earth
Rotation
Service
http://hpiers.obspm.fr
3.2
date
identification
of
a
particular
calendar
day,
expressed
by
some
combination
of
the
data
elements
calendar
year,
calendar
month,
calendar
week,
calendar
day
or
day
of
the
year
3.3
date,
calendar
identification
of
a
particular
calendar
day
by
its
calendar
year,
its
calendar
month
and
its
ordinal
number
within
its
calendar
month
3.4
date,
ordinal
identification
of
a
particular
calendar
day
by
its
calendar
year
and
its
ordinal
number
within
its
calendar
year
3.5
date,
week
identification
of
a
particular
calendar
day
by
the
calendar
year
to
which
its
calendar
week
belongs,
the
ordinal
number
of
its
calendar
week
within
that
year
and
its
ordinal
number
within
its
calendar
week
3.6
day
unit
of
time
of
24
hours
3.7
day,
calendar
time-interval
starting
at
[0000]
and
ending
at
[2400]
(which
is
equal
to
the
beginning
of
the
next
calendar
day);
typically
a
calendar
day
has
a
duration
of
24
h
NOTE
1
A
calendar
day
is
often
also
referred
to
as
day.
NOTE
2
The
duration
of
a
calendar
day
is
24
hours;
except
if
modified
by:
-
the
insertion
or
deletion
of
leap
seconds,
by
decision
of
the
IERS,
or
-
the
insertion
or
deletion
of
other
time
intervals,
as
may
be
prescribed
by
local
authorities
to
alter
local
time.
