date(1) USER COMMANDS date(1)
NAME
date - print and set the date
SYNOPSIS
date [ -u ] [ + format ]
date [ -a [ - ] sss.fff ] [ -u ] [[ mmdd]HHMM |
mmddHHMM[cc]yy ]
DESCRIPTION
If no argument is given, or if the argument begins with +,
the current date and time are printed. Otherwise, the
current date is set (only by super-user).
-a [ - ] sss.fff
Slowly adjust the time by sss.fff seconds (fff
represents fractions of a second). This adjust-
ment can be positive or negative. The system's
clock will be sped up or slowed down until it
has drifted by the number of seconds specified.
-u Display (or set) the date in Greenwich Mean Time
(GMT-universal time), bypassing the normal
conversion to (or from) local time.
mm is the month number
dd is the day number in the month
HH is the hour number (24 hour system)
MM is the minute number
cc is the century minus one
yy is the last 2 digits of the year number
The month, day, year, and century may be omit-
ted; the current values are supplied as
defaults. For example:
date 10080045
sets the date to Oct 8, 12:45 AM. The current
year is the default because no year is supplied.
The system operates in GMT. date takes care of
the conversion to and from local standard and
daylight time. Only the super-user may change
the date. After successfully setting the date
and time, date displays the new date according
to the default format. The date command uses TZ
to determine the correct time zone information
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date(1) USER COMMANDS date(1)
(see environ(5)).
+ format If the argument begins with +, the output of
date is under the control of the user. Each
Field Descriptor, described below, is preceded
by % and is replaced in the output by its
corresponding value. A single % is encoded by
%%. All other characters are copied to the out-
put without change. The string is always ter-
minated with a new-line character. If the argu-
ment contains embedded blanks it must be quoted
(see the EXAMPLE section).
Specifications of native language translations of month and
weekday names are supported. The month and weekday names
used for a language are based on the locale specified by the
environment variables LCTIME and LANG (see environ(5)).
The month and weekday names used for a language are taken
from a file whose format is specified in strftime(4). This
file also defines country-specific date and time formats
such as %c, which specifies the default date format. The
following form is the default for %c:
%a %b %e %T %Z %Y
e.g., Fri Dec 23 10:10:42 EST 1988
Field Descriptors (must be preceded by a %):
a abbreviated weekday name
A full weekday name
b abbreviated month name
B full month name
c country-specific date and time format
d day of month - 01 to 31
D date as %m/%d/%y
e day of month - 1 to 31 (single digits are preceded
by a blank)
h abbreviated month name (alias for %b)
H hour - 00 to 23
I hour - 01 to 12
j day of year - 001 to 366
m month of year - 01 to 12
M minute - 00 to 59
n insert a new-line character
p string containing ante-meridiem or post-meridiem
indicator (by default, AM or PM)
r time as %I:%M:%S %p
R time as %H:%M
S second - 00 to 61, allows for leap seconds
t insert a tab character
T time as %H:%M:%S
U week number of year (Sunday as the first day of the
week) - 00 to 53
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date(1) USER COMMANDS date(1)
w day of week - Sunday = 0
W week number of year (Monday as the first day of the
week) - 00 to 53
x Country-specific date format
X Country-specific time format
y year within century - 00 to 99
Y year as ccyy (4 digits)
Z timezone name
EXAMPLE
The command
date '+DATE: %m/%d/%y%nTIME: %H:%M:%S'
generates as output:
DATE: 08/01/76
TIME: 14:45:05
DIAGNOSTICS
No permission You are not the super-user and you try to
change the date.
bad conversion The date set is syntactically incorrect.
NOTES
Should you need to change the date while the system is run-
ning multi-user, use the datetime command of sysadm(1M). If
you attempt to set the current date to one of the dates that
the standard and alternate time zones change (for example,
the date that daylight time is starting or ending), and you
attempt to set the time to a time in the interval between
the end of standard time and the beginning of the alternate
time (or the end of the alternate time and the beginning of
standard time), the results are unpredictable.
SEE ALSO
sysadm(1M), strftime(4), environ(5) in the System
Administrator's Reference Manual.
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