Shell Programming and Scripting

$ date -d 'Jan 10, 2012' '+%s'
1326175200

$ date -d 'Jan 10 2012' '+%s'
1326175200

$

#!/bin/bash

SEC_IN_DAY=86400
EXP_DATE=`date -d 'May 17, 2012' '+%s'`
echo "Expiration date is set to May 17, 2012 and the seconds are $EXP_DATE"
SEVEN_DAYS=$(( $SEC_IN_DAY * 7))
TODAY_IN_SEC=`date '+%s'`
echo "Today in seconds is $TODAY_IN_SEC \'s"
SEVEN_DAYS_FROM_NOW=$(( $TODAY_IN_SEC + $SEVEN_DAYS))
echo "Seven days from now is $SEVEN_DAYS_FROM_NOW in seconds"
echo "Performing Test........."

#if [ "$EXPIRE_TIME" -le "$SEVEN_DAYS_FROM_NOW" ]
if test $EXPIRE_TIME -le "$SEVEN_DAYS_FROM_NOW
        then
                echo "Password is about to expire in seven days"
                echo "Please change your password"
fi