Date, time arithmetic, math
1) gnu date
2) ksh ( version 93, not 88; ksh93 M 93t+ ) printf, e.g:
printf "%(%Y-%m-%d)T\n" "yesterday"
Many more examples ( as of 2017.07 ):
http://blog.fpmurphy.com/2008/10/ksh93-date-manipulation.html
3) date.pl (perl, limited arithmetic, but "date.pl -d '- 1 day'" works)
( https://www.unix.com/tips-tutorials/239167-general-purpose-date-script.html )
4) dconv et al, e.g. ddiff, dconv, strptime (parsing), etc.
( dateutils: http://www.fresse.org/dateutils/ )
5) tm2tm (c, OK in 32-bit; fails to compile in 64-bit)
( https://www.unix.com/shell-programming-scripting/146216-date-difference-between-freebsd-linux.html#post302463136 )
6) perl custom formatting (with function POSIX::strftime, "perldoc POSIX")
Generally, see http://search.cpan.org/search?query=date&mode=all
7) date-cpan.pl, cpan perl date
( http://cpansearch.perl.org/src/CWEST/ppt-0.14/src/date/date.jgross )
8) For small changes, say, "yesterday" in bash, ksh
TZ=CST+24 date +%Y%m%d
csh, tcsh
setenv TZ CST+24 ; date +%Y%m%d
9) Check for legal date:
manstat:validata ( http://oldwww.acm.org/perlman/stat/ )
10) Check for legal date:
validate (local perl code)
11) Shell, ksh, date calculations:
www.unix.com/unix-for-dummies-questions-and-answers/4870-days-elapsed-between-2-dates.html
Hello, using date, we can easily get today's date
$ date +%y-%m-%d
06-12-08
is it possible for me to get yesterday's date using 'date', if not, is there any quick and easy way to do that?
Thanks! (1 Reply)
I am not using GNU nor BSD. On AIX, how do you return yesterday in the format of i.e. "May 09" with a space.
# `TZ=y380 date +%h""%d`
>> May09
# `TZ=y380 date +%h" "%d`
>> May
I appreciate your help in advance.
thx (3 Replies)
I haven't been using linux very long( and when I say that its only been about 1 week for me) I was told to do the following:
Create a Bash script that will copy all the files and subdirectories in one directory to a newly created directory. You may name the receiving directory anything you like.... (4 Replies)
I was playing to find a simple way to get yesterday's date, and came up with this (on an AIX 5.2 box):
$ date
Thu Feb 19 11:21:26 EST 2009
$ echo $TZ
EST5EDT
$ yesterday=`TZ=$(date +%Z)+24 date`
$ echo $yesterday
Wed Feb 18 16:21:52 GMT 2009
Why it is converted to GMT instead of... (2 Replies)
Hi,
`date` command will give the current days date.
Is there any command to get the previous day date?
I need the previous day value in my script.
Ahamed. (1 Reply)
HI All,
I am trying so long to find the yesterday's date to run a script but i failed
kinldy share the command to find yesterday's date in ksh
i tried with
date --date='1 day ago'
but it displaying error
your help will highly apeerciated.
Thanks (7 Replies)
Hi Friend,
i am using OS
HP-UX vvftf320 B.11.11 U 9000/800 511076331 unlimited-user license
now i have used below command but it giving today's date. i need your help to get yesterdate. Please correct me.
date +"%d%m%Y%H%M%S" -d "1 days ago
Thanks in advance,
Jewel (3 Replies)
Discussion started by: Jewel
3 Replies
LEARN ABOUT REDHAT
date::parse
Date::Parse(3) User Contributed Perl Documentation Date::Parse(3)NAME
Date::Parse - Parse date strings into time values
SYNOPSIS
use Date::Parse;
$time = str2time($date);
($ss,$mm,$hh,$day,$month,$year,$zone) = strptime($date);
DESCRIPTION
"Date::Parse" provides two routines for parsing date strings into time values.
str2time(DATE [, ZONE])
"str2time" parses "DATE" and returns a unix time value, or undef upon failure. "ZONE", if given, specifies the timezone to assume when
parsing if the date string does not specify a timezome.
strptime(DATE [, ZONE])
"strptime" takes the same arguments as str2time but returns an array of values "($ss,$mm,$hh,$day,$month,$year,$zone)". Elements are
only defined if they could be extracted from the date string. The $zone element is the timezone offset in seconds from GMT. An empty
array is returned upon failure.
MULTI-LANGUAGE SUPPORT
Date::Parse is capable of parsing dates in several languages, these are English, French, German and Italian. Changing the language is done
via a static method call, for example
Date::Parse->language('German');
will cause Date::Parse to attempt to parse any subsequent dates in German.
This is only a first pass, I am considering changing this to be
$lang = Date::Language->new('German');
$lang->str2time("25 Jun 1996 21:09:55 +0100");
I am open to suggestions on this.
EXAMPLE DATES
Below is a sample list of dates that are known to be parsable with Date::Parse
1995:01:24T09:08:17.1823213 ISO-8601
1995-01-24T09:08:17.1823213
Wed, 16 Jun 94 07:29:35 CST Comma and day name are optional
Thu, 13 Oct 94 10:13:13 -0700
Wed, 9 Nov 1994 09:50:32 -0500 (EST) Text in ()'s will be ignored.
21 dec 17:05 Will be parsed in the current time zone
21-dec 17:05
21/dec 17:05
21/dec/93 17:05
1999 10:02:18 "GMT"
16 Nov 94 22:28:20 PST
BUGS
When both the month and the date are specified in the date as numbers they are always parsed assuming that the month number comes before
the date. This is the usual format used in American dates.
The reason why it is like this and not dynamic is that it must be deterministic. Several people have suggested using the current locale,
but this will not work as the date being parsed may not be in the format of the current locale.
My plans to address this, which will be in a future release, is to allow the programmer to state what order they want these values parsed
in.
AUTHOR
Graham Barr <gbarr@pobox.com>
COPYRIGHT
Copyright (c) 1995 Graham Barr. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same
terms as Perl itself.
perl v5.8.0 2002-06-06 Date::Parse(3)