打印work week的起止日期

出于工作原因，经常要写的工作周报中要用到work week的起止日期，

下面这个bash脚本可以打印出需要的格式。

#!/bin/sh

function usage() {
cat<<EOT

Usage:
$0 20120315
$0 \`date -d "7 days ago" +%x\`

EOT
}

if [ $# -gt 1 ]; then
  usage
  exit 1
fi

if [ $# -eq 1 ]; then
  USER_DATE=$1
else
  USER_DATE=`date -d "7 days ago" +%x`
fi

DAY_OF_WEEK=$(date -d "$USER_DATE" '+%w')
DAY_OF_WEEK=`expr $DAY_OF_WEEK - 1`

# work week of the year
WORK_WEEK_OF_YEAR=$(date -d "$USER_DATE" '+%y%W')

# first day of the week
FIRST_DAY_OF_WEEK=$(date -d "$USER_DATE -$DAY_OF_WEEK days" '+%d %b %Y')

# last day of the week
LAST_DAY_OF_WEEK=$(date -d "$FIRST_DAY_OF_WEEK +4 days" '+%d %b %Y')

echo ""
echo "Work Week Caculator: $USER_DATE"
echo ""
echo "  Work week of the year:"
echo ""
echo "  $WORK_WEEK_OF_YEAR"
echo ""
echo "  $FIRST_DAY_OF_WEEK - $LAST_DAY_OF_WEEK"
echo ""