exiftool examples (manipulate creation date)

# precondition: folder with crappy jpg file names, like 002.JPG
# command below renames all files to each file's creation date

exiftool '-filename<CreateDate' -d %Y-%m-%d_%H.%M.%S%%-c.%%le -r /your/folder

# result file name 2009-01-14_07.16.46.jpg

# manipulate CreateDate (i.e. used by Google Photos)
# command below adds 54 minutes to all images in current folder (-m hides minor warnings/errors)
exiftool '-CreateDate+=0:0:0 0:54:0' -m .

# copy the "Date Time Original" in "File Modification Date"
exiftool "-filemodifydate<datetimeoriginal" .