Download photos and keep their original date

I just tried it ... and no matter what I do, the original (very fragile file dates) are preserved. Internal "golden standard" metadata date was always the same.

I took a photo in iOS 15.7.9 and transferred it to macOS 13.5.2 with

a) the default AirDrop settings (that transfers also some metadata edited in the iOS)

b) AirDrop with its "AllPhotosData" option (that transfers the original photo)

c) via USB and ImageCapture (that transfers the original photo).

exiftool -a -G1 -s -FileCreateDate -FileModifyDate -DateTimeOriginal .
======== ./IMG_1954_AirDrop_default.JPG
[MacOS]         FileCreateDate                  : 2023:09:21 15:08:06+03:00
[System]        FileModifyDate                  : 2023:09:21 15:08:06+03:00
[ExifIFD]       DateTimeOriginal                : 2023:09:21 15:08:06
======== ./IMG_1954_AirDrop_AllPhotosData.JPG
[MacOS]         FileCreateDate                  : 2023:09:21 15:08:06+03:00
[System]        FileModifyDate                  : 2023:09:21 15:08:06+03:00
[ExifIFD]       DateTimeOriginal                : 2023:09:21 15:08:06
======== ./IMG_1954_imagecapture.JPG
[MacOS]         FileCreateDate                  : 2023:09:21 15:08:06+03:00
[System]        FileModifyDate                  : 2023:09:21 15:08:06+03:00
[ExifIFD]       DateTimeOriginal                : 2023:09:21 15:08:06

You probably can't.

There are two kinds of metadata involved when you consider jpeg or other image file.

One is the file data. This is what the Finder shows. This tells you nothing about the contents of the file, just the File itself. The problem with File metadata is that it can easily change as the file is moved from place to place or exported, e-mailed, uploaded etc.

Photographs have also got both Exif and IPTC metadata. The date and time that your camera snapped the Photograph is recorded in the Exif metadata. Regardless if what the file date says, this is the actual time recorded by the camera. Photo applications like Photos, Lightroom, Photoshop etc get their date and time from the Exif metadata not the file date.

When you export from iPhoto to the Finder new file is created containing your Photo (and its Exif). The File date is - quite accurately - reported as the date of Export. However, the Photo Date doesn't change. The problem is that the Finder doesn't work with Exif. So, your photo has the correct date, and so does the file, but they are different things. You can edit the file creation date to match the Exif using a variety of apps, among them

https://www.publicspace.net/ABetterFinderAttributes/