Most web pages (themselves) are dynamic these days, that is, they are assembled (usually from within different parts of a database) when you browse them.
In any case, meta information (such as the sort of dates you are after) is not usually sent to the client (i.e, you).
The only option like this that is available to you is to look at the source of the page (usually from a pull-down menu option; on Firefox, View -> Page Source) to see if any such information has been included (very unlikely). This would not be in any sort of standard format if it is included.
Regards,
Script Wrecked.
