In the first form, print the current date and time,
specifying an optional display
format
.
In the second form, a privileged user can set the current date by supplying
a numeric
string
.
format
can consist of literal text strings (blanks must be quoted)
as well as field descriptors, whose values will appear as described below
(the listing shows some logical groupings).
-
%n
-
Insert a newline.
-
%t
-
Insert a tab.
-
%m
-
Month of year (01-12).
-
%d
-
Day of month (01-31).
-
%y
-
Last two digits of year (00-99).
-
%D
-
Date in
%m/%d/%y
format.
-
%b
-
Abbreviated month name.
-
%e
-
Day of month (1-31); pad single digits with a space.
-
%Y
-
Four-digit year (e.g., 1996).
-
%h
-
Same as
%b
.
-
%B
-
Full month name.
-
%H
-
Hour in 24-hour format (00-23).
-
%M
-
Minute (00-59).
-
%S
-
Second (00-61); 61 permits leap seconds.
-
%R
-
Time in
%H:%M
format.
-
%T
-
Time in
%H:%M:%S
format.
-
%I
-
Hour in 12-hour format (01-12).
-
%p
-
String to indicate a.m. or p.m. (default is AM or PM).
-
%r
-
Time in
%I:%M:%S %p
format.
-
%a
-
Abbreviated weekday.
-
%A
-
Full weekday.
-
%w
-
Day of week (Sunday = 0).
-
%U
-
Week number in year (00-53); start week on Sunday.
-
%W
-
Week number in year (00-53); start week on Monday.
-
%j
-
Julian day of year (001-366).
-
%Z
-
Time zone name.
-
%x
-
Country-specific date format.
-
%X
-
Country-specific time format.
-
%c
-
Country-specific date and time format
(default is
%a %b %e %T %Z %Y
;
e.g., Mon Feb 1 14:30:59 EST 1993).
The preceding country-specific formats, as well as language names
(e.g., for month and weekday)
are defined in a file given by
strftime
(4).
-
-a
s
.
f
-
(Privileged user only.) Gradually adjust the system clock until
it drifts
s
seconds away from
what it thinks is the "current" time.
(This allows continuous micro-adjustment of the clock while the
system is running.)
f
is the fraction of seconds by which time drifts.
By default, the clock speeds up; precede
s
by a
-
to slow down.
-
-u
-
Display or set the time using Greenwich Mean Time.
A privileged user can set the date by supplying a numeric
string
.
string
consists of time, day, and year
concatenated in one of three ways:
time
or
[
day
]
time
or [
day
]
time
[
year
].
Note: You don't type the brackets.
-
time
-
A two-digit hour and two-digit minute (
HHMM
);
HH
uses 24-hour format.
-
day
-
A two-digit month and two-digit day of month (
mmdd
);
default is current day and month.
-
year
-
The year specified as either the full four digits or
just the last two digits; default is current year.
Set the date to July 1 (
0701
), 4 a.m. (
0400
), 1995 (
95
):
date 0701040095
The command:
date +"Hello%t Date is %D %n%t Time is %T"
produces a formatted date as follows:
Hello Date is 05/09/93
Time is 17:53:39