Useful listing of days in a month to populate directories or run scripts for backing up getting the correct dates of days in a month and year.
YEAR=2020
MONTH=2
for DAY in $(DAYS=`cal $MONTH $YEAR | awk 'NF {DAYS = $NF}; END {print DAYS}'` && seq -f '%02G' $DAYS) ;do
DATE="$YEAR-$MONTH-$DAY"
echo $DATE
done
nJoy 😉