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