Geotagging

With the new Photos app, it is no longer possible to geotag photos from within the App as we were able to do with iPhoto :-(
I have been looking for external apps to add the geotagging information to my photos before importing them into the Photos library.
In particular I have found a free one called GeoTag that seems to do the job well but it has a problem. When I save the geotagging information to the photo it also changes the date to today's date.
Clearly this does not sit well with the Photos app as it relies so heavily on organising the photos by date.

Does anyone know of a geotagging app that will not change the photo date when I amend the location information to an image?

(Please refrain from suggesting I stop using Photos and instead I should be using iPhotos/Picasa/Lightroom/Whatever else. This is not what I am asking)

 

Replying to my own post so that it might help others.
I have actually found an app called HoudaGeo which achieves the purpose I have highlighted above, i.e. assigning a geotag without changing the timestamp.
Unfortunately HoudaGeo sets out to do all sort of other stuff I am not interested about, and for that it costs $29
Also unfortunately, it is not yet fully integrated with the new Photos app, so not as useful as it might become in the future.

In the meantime I have experimented with tagging (keywords) in Photos and I found that this function has been very well implemented and therefore it is as useful as GeoTagging for the moment.

That is probably good enough for me. Although it is scary the amount of time we spend creating metadata for our files only to have Apple deciding that they are not going to support the software any longer, just like that.
Staying on iPhotos is not really an option as it has no future.