Automator shell step. Receives a list of photo files, extract the date from their name, set the date as EXIF tag, move the file to a directory named after the date, and pass it to the next step.

getdate.sh

#!/bin/bash

dossier_ok=~/Desktop/Importes

for filepath in "$@"
do
	((n++))
	filename=$(basename $filepath)
	IFS='_' read -a array <<< "$filename"
	year=${array[0]}
	if ! [[ $year =~ [0-9]{4} ]] ; then continue; fi # Annee incorrecte
	month=${array[1]}
	if ! [[ $month =~ [0-9]{2} ]] ; then continue; fi # Mois incorrect
	day=${array[2]}
	if ! [[ $day =~ [0-9]{2} ]] ; then continue; fi # Jour incorrect
	#echo "Processing ${filename}..."
	exiftool -q −overwrite_original_in_place "-CreateDate=${year}:${month}:${day} 10:00:${n}" "${filepath}"
	exiftool -q −overwrite_original_in_place "-DateTimeOriginal=${year}:${month}:${day} 10:00:${n}" "${filepath}"

	# Create the folder
	ok_dir="${dossier_ok}/${year}/${month}"
	mkdir -p $ok_dir

	# Move the file
	dest="${ok_dir}/${filename}"
	#echo "cp \"${filepath}\" \"${dest}\""
	mv "${filepath}" "${dest}"
	echo $dest
done