zp-config.php.example should be edited in a text editor with your database login information, and then renamed zp-config.php. If you already have a zp-config.php (that setup created, for example) then you can delete the .example version, it's just there as a starting point.
Sounds like you're making this more complicated than it is.
The steps are:
zp-config.php.example file in a text editor.zp-config.phpThat's it! Then navigate to the setup page, at [http://your-web-site.com]/[zenphoto-install-dir]/zp-core/setup.php
So, you're correct, zp-config.php should not exist yet, until you follow the above procedure to create it. The date or whatever you were looking at means nothing, just follow the steps.
You could have also looked at the readme.txt file, or the installation instructions. Those are usually a good place to start, and tell you exactly how to do everything. And, as always with computers, don't be afraid to just experiment and try things.