UNIX for Dummies Questions & Answers

I have the following script to find out the last day of the last month .... and the output of this script is in the following format ...

Script goes like this ....

#!/bin/ksh
cur_month=`date +%m`
cur_year=`date +%Y`
prev_month=$(($cur_month-1))

# Check to see if this is January
if [ $prev_month -lt 1 ]
then
prev_year=$(($cur_year-1))
prev_month=12
LastDayOfLastMonth=`/bin/cal $prev_month $cur_year | grep -v "^$" | sed -n '1p;$p' | tr "\n" " " | awk '{print substr($1,1,3),$N
F,$2}'`
else
LastDayOfLastMonth=`/bin/cal $prev_month $cur_year | grep -v "^$" | sed -n '1p;$p' | tr "\n" " " | awk '{print substr($1,1,3),$N
F,$2}'`
fi
echo $LastDayOfLastMonth

Output will be like this ...
May 31 2008

I want this output to be converted to the following format and displayed ...
2008-05-31 -- This is the format i need the output to be

Please help me with this .... Thx

man date....

# date '+DATE: %Y-%m-%d'
DATE: 2008-06-17

is there a way we can get the output of the above script in the following format ..... like ... yyyy-mm-dd

the above mentioned script gives me output as " May 31 2008"

???
Watch:
on a IBM AIX:
vbe@ ello9: /home/vbe# uname
AIX
vbe@ ello9: /home/vbe# oslevel
5.3.0.0
vbe@ ello9: /home/vbe# date '+DATE: %Y-%m-%d'
DATE: 2008-06-17
vbe@ ello9: /home/vbe#

Now SUN
olf:/export/home/vbe # more /etc/release
Solaris 9 12/02 s9s_u2wos_10a SPARC
Copyright 2002 Sun Microsystems, Inc. All Rights Reserved.
Use is subject to license terms.
Assembled 02 December 2002
olf:/export/home/vbe # date '+DATE: %Y-%m-%d'
DATE: 2008-06-17
olf:/export/home/vbe #

HP HPUX?
ant:/home/vbe $ uname -a
HP-UX ant B.11.11 U 9000/800 16..1511 unlimited-user license
ant:/home/vbe $ date '+DATE: %Y-%m-%d'
DATE: 2008-06-17
ant:/home/vbe $

READ the man pages!!!

Thanks vbe ...
I think my question was bit confusing ... let me tell you what exactly i need ..

I have provided a script in my 1st post ... in that script .... i'm just selecting particular peices of information from $cal (calender) to get the last day of last month ....
and here ... i'm picking up month name, last date and year using grep, sed, tr, awk .... displaying it in the format "May 31 2008" (this just a string of data) ... and i want this output string (that is $LastDayOfMonth in my script) to be converted to a specific format (that is yyyy-mm-dd) ...

Did you have a look at perderabo's script?
https://www.unix.com/unix-dummies-que...html#post16559

even though his script is a good one ... but it is not of much help to me with the present issue I have ...
it would be gr8 if someone can help me get the first day of last month and last day of last month in yyyy-mm-dd format.