Shell Programming and Scripting

Hi,

I have 2 problem if i type the date in %d/%m/%Y format at command prompt it "calculates a wrong date. But the same date if i give in %Y/%m/%d .it works.

pls can anyone assist on this as i want to check the d/m/YY format or it should say invalid date which i can trap.

problem 1)
date -d "30/12/2007 +1 day" +%d%m%Y
gives wrong date

but if i give
date -d "12/30/2007 +1 day" +%d/%m%Y

returns 12/01/2008 which is what it should return.

problem 2)

$1=12/30/2007
$2=12/15/2007

if [ $2 /< $1 ]
echo " to date $2 cannot be less then from date $1"
exit
fi

does not come out go to the next step in the script.

pls can any one help on this
Thanks

Problem 1
---------

Whether 12/30/2007 or 30/12/2007 is an invalid date depends on your locale setting.
12/30/2007 is valid in the US but an invalid date in, say, Ireland. On the other hand 30/12/2007 is a valid date in Ireland but an invalid date in the US.

Problem 2
---------

The simplist solution is to convert the two dates to Julian dates i.e. integers and then compare the integers.