Find out the last modified date of the web page you are viewing
Here’s a trick I just learned:
Javascript Bonus: Curious about when the page you’re on was last updated? Just type javascript:alert(document.lastModified) in the address bar and press Enter to see the date and time in a pop-up window.
And here’s a link (Last Modified) can drag to your toolbar. Once there, you can click on it on any page.

