Using the file date, move the file into a directory named YEAR-MON. The directory is created if it doesn't exist.

organize_by_year_month.sh

#/usr/local/bin/bash

DST_DIR=~/Photos/exports

# Organizes files by year/month into the DST_DIR
find . -type f | \
    while read i; \
    do IFS=' '  read -r -a result <<< $(ls -lUTD %Y-%m "$i");\
       mkdir -p $DST_DIR/${result[5]};\
       mv "$i" $DST_DIR/${result[5]};\
    done