You should decouple three programming concerns. (I use Linux commands, but they work with Cygwin and MinGW, too).

1. Finding and listing files. This can be done with find -iname "..." through folders.

2. Extracting EXIF data. This can be done with exiftool.

1+2 can be easily coupled with xargs. E.g. this command lists all tags related to "Date" (it is one line, no line break intended). You should pick one for further processing.

find -iname "*.NEF" -print0 | xargs -0 -I {} exiftool -d "%Y, %m, %d" -All {} | grep "Date"

E.g. you can pick "Create Date" and filter for that in exiftool.

By the way, if you want to see all time information for a file, use:

exiftool -time:all -a -G0:1 -s myimage.NEF

And if your files are all within subdirectories, you can use the -r option (and skip the find command obviously.)

Now, this command outputs ALL the time information available, for your postprocessing:

find -iname "*.NEF" -print0 | xargs -0 -I {} exiftool -csv -time:all -filename -a -G0:1 {} >outputlist.txt

3 . Sorting, filtering. Now, this should be easy, use your constraints.

The very easiest is to pull the data into Excel and apply filters, or better, import to an SQL database, and query whatever you would like to query. You will see that different files contain different amount of timestamp data, and you have to reconcile that.

An alternative is to use the -X option instead of -csv, and generate XML output. This may or may not be easier to postprocess for you.

Now, if you are sure that e.g. CreateDate is what you need, you could try this:

find -iname "*.NEF" -print0 | xargs -0 -I {} exiftool -T -d "#Year#%Y# #Month#%m# #Day#%d#" -filename -CreateDate {} | grep "#Month#05#" | grep "#Day#07#"

I think it is obvious how I spiced up the initial find+exiftool command. It will find any images with the creation date having month == May and day == 7.

Good luck! ;-)