comparison where ONLY the modification date is checked

[kohlhaas]

I would welcome it if there was a comparison method in which ONLY the modification date (apart from the name) was checked.

The reason for this:
I have about 100GB of image files in a folder structure.
I have the same folder structure for my mobile devices, but with resized images.
Resizing the images is not a problem (mogrify in Linux), but I would like to have a tool to check if the two folder structures are still congruent.

[xCSxXenon]

A sync program is not the right tool for that as you aren't trying to sync anymore

[kohlhaas]

Sorry, I can't agree:

It should indeed be synchronised, but only on the basis of the file name and date.
I would just like to leave out the size ...