dateutils' ordinal date format doesn't doesn't work; and everyone is still writing things in Python, so... ordinal dates in Shell

orddate

#!/bin/sh
today=$(date +'%A %e %B %Y') # obviously you can modify this line
D=$(echo $today | grep -E -o "(\b(|[0-3])[0-9]\b)")
case $D in
1|21|31)
mod="st"
;;
2|22)
mod="nd"
;;
3|23)
mod="rd"
;;
*)
mod="th"
;;
esac
ordinal="$D$mod"
fulldate=${today/$D/$ordinal}
echo ${fulldate/  / }
exit