Check the date a webpage was last changed

When you browse the web, you sometimes want to know when the page you are viewing was last updated. While viewing the page in your browser, type the following in the address bar of your browser and hit Enter:

javascript:alert(document.lastModified);

It gives you a popup with the date the page was last updated.

Note:
It only works for static HTML pages, since dynamically created pages are created on the fly, that is, today.