Organize your Photos by Date Using Exiftool

Find all photos without date information

$ exiftool -filename -filemodifydate -createdate -r -if '(not $datetimeoriginal) and $filetype eq "JPEG"' .

Set last created and modified to a specific date

$ find . -name "*.jpg" | while read filename;
exiftool "-AllDates=1986:11:05 12:00:00" "$filename";
done

Copy of the originals will be created. Remove *.jpg_original if everything went fine or add -overwrite_original parameter.

Timeshift

by one year

$ exiftool "-AllDates+=1:0:0 00:00:00" .

Rename your files to contain the date and time

they will be suffixed tith -N if they have the same date and time

$ exiftool '-FileName<DateTimeOriginal' -d "%Y%m%d_%H%M%S%%-c.%%e" *.jpg
$ exiftool '-FileName<DateTimeOriginal' -d "%Y-%m-%d %H.%M.%S%%-c.%%e" *.jpg

Copy your photos in a folder structure organised by datetime

exiftool '-Directory<CreateDate' -d ~/Dropbox/Photos/%y/%y%m -r .