DATE(1) User Commands DATE(1)

date - print or set the date

date [-u] [+format]
date [-u] [-b] HHMM | mmddHHMM[[cc]yy]
date -a [-]sss.fff

Date displays the current date if invoked without arguments or with a +format argument.

If the first argument does not start with +, date sets the system time to the given value, which may consist of

mm month of year (01–12)
dd day of month (01–31)
HH hour (00–23)
MM minute (00–59)
cc first two digits of year
yy second two digits of year

The following options alter the behavior of date:

Adjust the system clock by sss seconds and fff milliseconds, speeding up or, with -, slowing down.
Use UTC values for printing and setting the date.

The following option is an extension:

Causes date not to alter the `wtmp' file for the system time change.

An argument starting with + specifies a format string to print the current date. A percent character % introduces a field descriptor with one or two following characters which is replaced by a part of the current date, as shown in the table below. Other characters are printed literally. A newline character is printed at the end of the output.

a locale-specific abbreviated weekday name (System III)
A locale-specific full weekday name (SVID3, POSIX.2)
b locale-specific abbreviated month name (SVID3, POSIX.2)
B locale-specific full month name (SVID3, POSIX.2)
c locale-specific date and time (SVID3, POSIX.2)
C century – 19 or 20 (POSIX.2) (/usr/5bin/s42/date, /usr/5bin/posix/date, /usr/5bin/posix2001/date) default output format (/usr/5bin/date)
d day of month – 01 to 31 (System III)
D date as mm/dd/yy (System III)
e day of month – 1 to 31 (SVID3, POSIX.2)
F date as yyyy-mm-dd
g week-based year within century – 00 to 99
G week-based year including century – 0000 to 9999
h same as %b (System III)
H hour – 00 to 23 (System III)
I hour – 01 to 12 (SVID3, POSIX.2)
j day of year – 001 to 366 (System III)
m month of year – 01 to 12 (System III)
M minute – 00 to 59 (System III)
n newline character (System III)
N default output format
p locale-specific AM/PM string (SVID3, POSIX.2)
r locale-specific time using AM/PM notation (System III)
R same as %H:%M (SVID3)
S second – 00 to 61 (System III)
t tab character (System III)
T time as HH:MM:SS (System III)
u weekday – 1 (Monday) to 7 (POSIX.2)
U week of year (Sunday as first day of week) – 00 to 53 (SVID3, POSIX.2)
V week of year (Monday as first day of week) – 01 to 53 (POSIX.2)
w weekday – 0 (Sunday) to 6 (System III)
W week of year (Monday as first day of week) – 00 to 53 (SVID3, POSIX.2)
x locale-specific date (POSIX.2)
X locale-specific time (SVID3, POSIX.2)
y last two digits of year – 00 to 99 (System III)
Y four-digit year – 1970 to 2037 (SVID3, POSIX.2)
z numeric timezone
Z timezone name (SVID3, POSIX.2)
% percent sign (System III)
Ec alternative date and time (POSIX.2)
EC alternative base year (period) (POSIX.2)
Ex alternative date (POSIX.2)
EX alternative time (SUSv2)
Ey offset from %EC in years (POSIX.2)
EY full alternative year (POSIX.2)
Od day of month filled with leading zero using alternative numerals (POSIX.2)
Oe day of month filled with leading space using alternative numerals (POSIX.2)
OH 24-hour clok using alternative numerals (POSIX.2)
OI 12-hour clock using alternative numerals (POSIX.2)
Om month of year using alternative numerals (POSIX.2)
OM minute using alternative numerals (POSIX.2)
OS second using alternative numerals (POSIX.2)
Ou weekday (Monday = 1) using alternative numerals (POSIX.2)
OU week of year (cf. %U) using alternative numerals (POSIX.2)
OV week of year (cf. %V) using alternative numerals (POSIX.2)
Ow weekday (Sunday = 0) using alternative numerals (POSIX.2)
OW week of year (cf. %W) using alternative numerals (POSIX.2)
Oy year (offset from %C) using alternative numerals (POSIX.2)
System III AT&T System III manual page date(1).      
SVID3 AT&T System V Interface Definition, Third Edition, Volume II, 1992, date(BU_CMD). Includes all field descriptors present in System III.
POSIX.2 ISO/IEC 9945-2:1993(E), 4.15.4.1–4.15.4.2, pp. 241–242. Includes all field descriptors present in System III.
SUSv2 The Open Group, Single UNIX Specification, Version 2, © 1997, date(XCU). Includes all field descriptors present in POSIX.2.

When no arguments are given, the format defaults to

%a %b %e %H:%M:%S %Z %Y

in the C or POSIX locale, resulting in an output like

Wed Feb 26 17:48:54 CET 2003

See locale(7).
Alters the strings printed when format arguments are given.
Timezone; if unset, the system default is used.

adjtime(2), stime(2), strftime(3), locale(7)

After setting the date, the hwclock(8) utility is called to adjust the hardware clock on Linux systems.

1/24/05 Heirloom Toolchest