Working out weather a week is the 1st 2nd 3rd 4th week of the year

I needed a program to work out what week number it was for Radio station Log generation.... so I made this. It makes pretty boring reading...

#!/bin/bash

WEEK_NUM=`date +%V`

echo $WEEK_NUM

sleep 1
#DIV_WEEK=`expr $WEEK_NUM % 4`
#echo $DIV_WEEK

case "$WEEK_NUM" in
    01) export THIS_WEEK=1
    export WEEK2=2
    export WEEK3=3
    export WEEK4=4
    export WEEK5=1
    export WEEK6=2
    ;;
    02) export THIS_WEEK=2
    export WEEK2=3
    export WEEK3=4
    export WEEK4=1
    export WEEK5=2
    export WEEK6=3
    ;;
    03) export THIS_WEEK=3
    export WEEK2=4
    export WEEK3=1
    export WEEK4=2
    export WEEK5=3
    export WEEK6=4
    ;;
    04) export THIS_WEEK=4
    export WEEK2=1
    export WEEK3=2
    export WEEK4=3
    export WEEK5=4
    export WEEK6=5
    ;;
    05) export THIS_WEEK=1
    export WEEK2=2
    export WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
    06) export THIS_WEEK=2
    export WEEK2=3
    export WEEK3=4
    export WEEK4=1
    export WEEK5=2
    export WEEK6=3
    ;;
    07) export THIS_WEEK=3
    export WEEK2=4
    export WEEK3=1
    export WEEK4=2
    export WEEK5=3
    export WEEK6=4
    ;;
    08) export THIS_WEEK=4
    export WEEK2=1
    export WEEK3=2
    export WEEK4=3
    export WEEK5=4
    export WEEK6=5
    ;;
    09) export THIS_WEEK=1
    export WEEK2=2
    export WEEK3=3
    export WEEK4=4
    export WEEK5=1
    export WEEK6=2
    ;;
    10) THIS_WEEK=2
    WEEK2=3
    WEEK3=4
    WEEK4=1
    WEEK5=2
    WEEK6=3
    ;;
    11) THIS_WEEK=3
    WEEK2=4
    WEEK3=1
    WEEK4=2
    WEEK5=3
    WEEK6=4
    ;;
    12) THIS_WEEK=4
    WEEK2=1
    WEEK3=2
    WEEK4=3
    WEEK5=4
    WEEK6=5
    ;;
    13) THIS_WEEK=1
    WEEK2=2
    WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
    14) THIS_WEEK=2
    WEEK2=3
    WEEK3=4
    WEEK4=1
    WEEK5=2
    WEEK6=3
    ;;
    15) THIS_WEEK=3
    WEEK2=4
    WEEK3=1
    WEEK4=2
    WEEK5=3
    WEEK6=4
    ;;
    16) THIS_WEEK=4
    WEEK2=1
    WEEK3=2
    WEEK4=3
    WEEK5=4
    WEEK6=5
    ;;
    17) THIS_WEEK=1
    WEEK2=2
    WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
    18) THIS_WEEK=2
    WEEK2=3
    WEEK3=4
    WEEK4=1
    WEEK5=2
    WEEK6=3
    ;;
    19) THIS_WEEK=3
    WEEK2=4
    WEEK3=1
    WEEK4=2
    WEEK5=3
    WEEK6=4
    ;;
    20) THIS_WEEK=4
    WEEK2=1
    WEEK3=2
    WEEK4=3
    WEEK5=4
    WEEK6=5
    ;;
    21) THIS_WEEK=1
    WEEK2=2
    WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
    22) THIS_WEEK=2
    WEEK2=3
    WEEK3=4
    WEEK4=1
    WEEK5=2
    WEEK6=3
    ;;
    23) THIS_WEEK=3
    WEEK2=4
    WEEK3=1
    WEEK4=2
    WEEK5=3
    WEEK6=4
    ;;
    24) THIS_WEEK=4
    WEEK2=1
    WEEK3=2
    WEEK4=3
    WEEK5=4
    WEEK6=5
    ;;
    25) THIS_WEEK=1
    WEEK2=2
    WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
    26) THIS_WEEK=2
    WEEK2=3
    WEEK3=4
    WEEK4=1
    WEEK5=2
    WEEK6=3
    ;;
    27) THIS_WEEK=3
    WEEK2=4
    WEEK3=1
    WEEK4=2
    WEEK5=3
    WEEK6=4
    ;;
    28) THIS_WEEK=4
    WEEK2=1
    WEEK3=2
    WEEK4=3
    WEEK5=4
    WEEK6=5
    ;;
    29) THIS_WEEK=1
    WEEK2=2
    WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
    30) THIS_WEEK=2
    WEEK2=3
    WEEK3=4
    WEEK4=1
    WEEK5=2
    WEEK6=3
    ;;
    31) THIS_WEEK=3
    WEEK2=4
    WEEK3=1
    WEEK4=2
    WEEK5=3
    WEEK6=4
    ;;
    32) THIS_WEEK=4
    WEEK2=1
    WEEK3=2
    WEEK4=3
    WEEK5=4
    WEEK6=5
    ;;
    33) THIS_WEEK=1
    WEEK2=2
    WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
    34) THIS_WEEK=2
    WEEK2=3
    WEEK3=4
    WEEK4=1
    WEEK5=2
    WEEK6=3
    ;;
    35) THIS_WEEK=3
    WEEK2=4
    WEEK3=1
    WEEK4=2
    WEEK5=3
    WEEK6=4
    ;;
    36) THIS_WEEK=4
    WEEK2=1
    WEEK3=2
    WEEK4=3
    WEEK5=4
    WEEK6=5
    ;;
    37) THIS_WEEK=1
    WEEK2=2
    WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
    38) THIS_WEEK=2
    WEEK2=3
    WEEK3=4
    WEEK4=1
    WEEK5=2
    WEEK6=3
    ;;
    39) THIS_WEEK=3
    WEEK2=4
    WEEK3=1
    WEEK4=2
    WEEK5=3
    WEEK6=4
    ;;
    40) THIS_WEEK=4
    WEEK2=1
    WEEK3=2
    WEEK4=3
    WEEK5=4
    WEEK6=5
    ;;
    41) THIS_WEEK=1
    WEEK2=2
    WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
    42) THIS_WEEK=2
    WEEK2=3
    WEEK3=4
    WEEK4=1
    WEEK5=2
    WEEK6=3
    ;;
    43) THIS_WEEK=3
    WEEK2=4
    WEEK3=1
    WEEK4=2
    WEEK5=3
    WEEK6=4
    ;;
    44) THIS_WEEK=4
    WEEK2=1
    WEEK3=2
    WEEK4=3
    WEEK5=4
    WEEK6=5
    ;;
    45) THIS_WEEK=1
    WEEK2=2
    WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
    46) THIS_WEEK=2
    WEEK2=3
    WEEK3=4
    WEEK4=1
    WEEK5=2
    WEEK6=3
    ;;
    47) THIS_WEEK=3
    WEEK2=4
    WEEK3=1
    WEEK4=2
    WEEK5=3
    WEEK6=4
    ;;
    48) THIS_WEEK=4
    WEEK2=1
    WEEK3=2
    WEEK4=3
    WEEK5=4
    WEEK6=5
    ;;
    49) THIS_WEEK=1
    WEEK2=2
    WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
    50) THIS_WEEK=2
    WEEK2=3
    WEEK3=4
    WEEK4=1
    WEEK5=2
    WEEK6=3
    ;;
    51) THIS_WEEK=3
    WEEK2=4
    WEEK3=1
    WEEK4=2
    WEEK5=3
    WEEK6=4
    ;;
    52) THIS_WEEK=4
    WEEK2=1
    WEEK3=2
    WEEK4=3
    WEEK5=4
    WEEK6=5
    ;;
    53) THIS_WEEK=1
    WEEK2=2
    WEEK3=3
    WEEK4=4
    WEEK5=1
    WEEK6=2
    ;;
   
esac
echo 'this week is' $THIS_WEEK
echo 'week 2 is' $WEEK2
echo 'week 3 is' $WEEK3
echo 'week 4 is' $WEEK4
echo 'week 5 is' $WEEK5
echo 'week 6 is' $WEEK6

sleep 5
exit