Hi!

When uploading images by ftp, is it possible to set the image publish date the current date the image is being uploaded?

You could embeed the date in the image meta data (Exif). You could possible code something using available filters to use the current date (see the plugin tutorial).

It would require a feature enhancement in Zenphoto. Perhaps you can explain what your intended use is. The publish dates for images and albums were conceived as control for future publishing of unpublished items. So your request seems strange.