Shell Programming and Scripting

# Arg_1 = [DAYS:-1]
{
    days=${1:-1}
    date_d=`date +%d`
    date_m=`date +%m`
    date_y=`date +%Y`
	#--------------------------------
	# Days Back Size Test
	#--------------------------------
	if [ $days -lt $date_d ]
	then
		date_d=`expr $date_d - $days`
	else
		days=`expr $days - $date_d`
		date_m=`expr $date_m - 1`
		month_length=`s_month_length $date_m`
		while [ $days -gt $month_length ]
		do
			days=`expr $days - month_length`
			date_m=`expr $date_m - 1`
			month_length=`s_month_length $date_m`
		done
		date_d=`expr $month_length - $days`
	fi
	#--------------------------------
	# Date	String Padding
	#--------------------------------
	if [ $date_d -lt 10 ]
	then
		date_d="0"$date_d
	fi
	if [ $date_m -lt 10 ]
	then
		date_m="0"$date_m
	fi
	echo $date_y $date_m $date_d
}