Two questions here:

1. In archive view, which date fields are used to generate the list? If it uses ALL date fields as is suggested in archive.php - line 40 - <?php printAllDates(); ?> - Is it possible display dates from photos/videos only and NOT albums?

2. Because I use a lot of master albums that will never have any content other than sub-albums; is it possible to keep the master album date fields empty?

The date archive listing uses the "date" field of images so images (incl. non image image types like videos) only. Images from albums that are not public are not included.

It's perfect usage to have albums with either albums or images and not both as it is a cleaner structure to visitors. I prefer that as well.

OK, That answers my 1st question

But what about my 2nd - Is it possible to modify my theme or zp-core files so that I have the album date field empty?

What is the album date field used for if it not used in archive view?

Why do you want the album date to be empty? Since it has nothing to do with the archive view.

Anyway, you can set the date to empty on the album edit page, but it will not last as the date will be refreshed from the album folder's date any time a database refresh is done. It is also (optionally) updated whenever a new image is discovered.

The album date may not be used by the archive view but that does not make it obsolete. For example functions of the image_album_statistics plugin may use it.

It really does not do any harm if it is just set. If you just don't want it to be shown on theme, you can always edit the theme and remove the related function.

Thanks

I was just trying to understand what it was used for and your answers have made it clear - Thanks again.