after looking for some information I found a short JavaScript code in internet. javascript:alert(document.lastModified) You just copy and put it into the adressbar. After click to enter you get a popup with the date of the last updating.
http://simile.mit.edu/timeline/
Timeline is a DHTML-based AJAXy widget for visualizing time-based events
It provides bifocal-view, with variable granularity of the detail view (within one timeline!). User navigates intuitively by panning horizontally over one of the two time-ribbons. It requires zero installation, data input is simply by pointing to a xml file.
Drawback: In some cases it would be nice to be able, to connect events, to express some kind of relation.