It seems version 1.5 still not offers the option to sort the pictures on the "original date taken".
I did find a post on how to achieve in version 1.4 (http://forum.coppermine-gallery.net/index.php/topic,43278.0.html).
Since I wanted to have this functionality i have tried to convert those steps into a working solution for version 1.5.10.
The program at least does not stop ;D
Apart from adjusting the DB as described in the original article, i have added to this message all scripts that needed to be adjusted.
So backup the originals and have a go.
Hopefully one day this functionality ends up in core.
Be warned, scripts can only be used in version 1.5.10 !!
I'm aware the post says this can only be used in 1.5.10, but I was wondering if the post was made before security update 1.5.12, and since its just a security update, if it'd still work?
I couldn't get it to work but then I'm not sure if that's a problem with my implementation or that the script wouldn't work anyway.
I'd appreciate any advice.