date.1

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)date.1	3.2	9/7/88
.TH date 1
.SH Name
date \- print date and time
.SH Syntax
.B date
[\-c | \-u] [ \fB+\fPformat ] [[yy[mm[dd]]]hhmm[.ss][\-[\-]tttt][z]]
.SH Description
.NXR "date command"
.NXR "time command" "printing"
.NXR "time" "setting"
.NXR "date" "printing"
.NXR "date" "setting"
If no argument is given,
or if the argument begins with \fB+\fP,
the current date and time are printed.
Otherwise, the current date is set.
The first
.I mm
is the month number;\fR
.I dd
is the day number in the month;\fR
.I hh
is the hour number (24 hour clock);\fR
the second
.I mm
is the minute number;\fR
.I .ss
the second;\fR
-[-]\fItttt\fR
is the minutes west of Greenwich;\fR
a positive number means your time zone is west of Greenwich
(for example, North and South America)
and a negative number means it is east of Greenwich (for
example Europe);
.I z
is a one letter code indicating the dst correction mode
(n=none, u=usa, a=australian, w=western europe, m=middle europe,
e=eastern europe);
.I yy
is the last 2 digits of the year number and is optional.
The following example sets the date to Oct 8, 12:45 \s-1AM\s+1:
.EX
date\| 10080045
.EE
The current year is the default if no year is mentioned.
The system operates in \s-1GMT\s0.
The
.PN date
takes care of the conversion to and from
local standard and daylight time.
.PP
If the argument begins with \fB+\fP,
the output of
.PN date
is under the control of the user.
The format for the output is similar to that of
the first argument to
.MS printf 3s .
All output fields are of fixed size (zero padded
if necessary).
Each field descriptor is preceded by \fB%\fP
and is replaced in the output by
its corresponding value.
A single \fB%\fP is encoded by \fB%%\fP.
All other
characters are copied to the output without change.
The string is always terminated with a new-line character.
.SH Options
.TP
.B \-c
Perform operations using Coordinated Universal Time (UCT) instead
of the default local time. The UCT does not use leap seconds so
UCT is the same as GMT.
.TP
.B \-u
Perform operations using Greenwich Mean Time (GMT) instead of the
default local time.
.TP
.B + \fIformat\fR
The following is a list of field Descriptors that can be used in the
format (Note: date exits after processing format information) :
.NXR "date command" "field descriptors"
.RS 10
.TP 5
.B %a
Locale's abbreviated weekday name
.TP 
.B %A
Locale's full weekday name
.TP 
.B %b
Locale's abbreviated month name
.TP 
.B %B
Locale's full month name
.TP 
.B %c
Locale's date and time representation
.TP 
.B %d
Day of month as a decimal number (01\-31)
.TP 
.B %D
Date (%m/%d/%y)
.TP 
.B %h
Locale's abbreviated month name
.TP 
.B %H
Hour as a decimal number (00\-23)
.TP 
.B %I
Hour as a decimal number (01\-12)
.TP 
.B %j
Day of year (001\-366)
.TP 
.B %m
Number of month (01\-12)
.TP 
.B %M
Minute number (00\-59)
.TP 
.B %n
Newline character
.TP 
.B %p
Locale's equivalent to AM or PM
.TP 
.B %r
Time in AM/PM notation
.TP 
.B %S
Second number (00\-59)
.TP 
.B %t
Tab character
.TP 
.B %T
Time (%H/%M/%S)
.TP 
.B %U
Week number (00\-53), Sunday as first day of week
.TP 
.B %w
Weekday number (0[Sunday]\-6)
.TP 
.B %W
Week number (00\-53), Monday as first day of week
.TP 
.B %x
Locale's date representation
.TP 
.B %X
Locale's time representation
.TP 
.B %y
Year without century (00\-99)
.TP 
.B %Y
Year with century
.TP 
.B %Z
Timezone name, no characters if no timezone
.TP 
.B %%
%
.RE
.SH Examples
.NXR(e) "date command"
The following command line
.EX
date\| +%m/%d/%y
.EE
generates the following output
.EX
04/02/89
.EE
The following command line
.EX
date\| +"DATE: %m/%d/%y%nTIME: %H:%M:%S"
.EE
generates the following output
.EX
DATE: 04/02/89
.br
TIME: 14:45:05
.EE
The quotes (") are necessary because the \fIformat\fR contains blank
characters. Use single quotes (') to prevent interpretation by the
shell.
.SH Diagnostics
.NXR(c) "date command" "diagnostics"
.TP .5i
.B "Failed to set date: Not owner"
You are not the super-user and you tryed to change the date.
.NT CAUTION	 
.NXR(c) "date command" "multiuser mode and"
Do not change the date while the system is
running in multiuser mode.
.NE
.SH Restrictions
An attempt to set a date to before 1/1/1970 will result in 
the date being set to 1/1/1970.
.SH Files
/dev/kmem