[qw]

"last modified" only works for static content, and not pages that are rendered dynamically or where the header is set based on cache settings.

Even for static content, the date may be wrong as the output may have been generated multiple times since it was first created.

[shishironline]

Thanks for the info

[iggldiggl]

Wordpress-based blogs (maybe others, too) often have a timestamp hidden in an HTML Meta-tag even if the date is otherwise hidden from regular view.