Script with problem for getting dates

[Rita Li]

Hi,

Today is Oct-1-2007, a Monday date. My script runs werid that is to start with getting the last Sunday date, then the Monday date before this Sunday date.

day1=`date "+%Y%m%d"`
day2=`date +%w`
if [ $day2 -eq 0 ]; then
sun_day=$day1
else
sun_day=`date +%Y%m%d-$day2|bc`
fi
mon_day=`date +%Y%m%d-$day2-6|bc`
echo $sun_day $mon_day

The result produced is:

20071000 20070994

Pls render help

Rita

[Steven Schweda · Accepted solution]

What's weird? 20071001 - 1 = 20071000, and
20071001 - 1 - 6 = 20070994. You got what
you asked for.

The result of "date '+%Y%m%d'" is not an
ordinary decimal number, so you can't do
ordinary decimal arithmetic on it and get
a resonable answer, except by luck.

You might look at the suggestions for a
similar problem at:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1040167

[TY 007]

Hello Rita,

date '+%m %d %Y' |
{
read MONTH DAY YEAR
DAY=`expr "$DAY" - 1`
case "$DAY" in
0)
MONTH=`expr "$MONTH" - 1`
case "$MONTH" in
0)
MONTH=12
YEAR=`expr "$YEAR" - 1`
;;
esac
DAY=`cal $MONTH $YEAR | grep . | fmt -1 | tail -1`
esac
sun_day=$YEAR/$MONTH/$DAY
mon_day=`date +%Y/%m/%d`
echo $sun_day $mon_day
}

The result produced is:

2007/9/30 2007/10/01

Please modify above script further.

Thanks

[Rita Li]

A. Clay's script is great

Problem is fixed

Thank you for the prompt respond

Rita