How to preserve original capture date when downloading photos from a shared album?

Are you asking about the time stamp of the saved file or the exif capture date embedded in the saved file?

previously we could not even share photos in Shared albums with the capture date, because the date has been stripped for privacy reasons. But since iOS 17 the capture date can be shared and is embedded in the exif tags of the shared photo and we can even sort the photos in the shared albums by the date.

But the file creation date is modified, because we are not sharing the original file but Photos is creating a new, smaller file, optimized for sharing, and we are sharing this new copy. The file creation date will be the day this new version has been created. And it may change again, when you download the file from iCloud. But the capture date will be preserved in the exif tags.

It will on the way you download the file from the shared album, if the file creation date will reflect the capture date or not. When I download a photo from a shared album in the Photos.app on my Mac and export it from photos to a folder on my Mac, Photos will automatically set the file creation date of the exported version to the date the photo has been taken.

When downloading photos from a shared album on devices like Apple, the timestamps may change to the upload or download time. To preserve the original capture date, you can try downloading the photos directly from the original source or use a third-party tool that retains the metadata.