Determine last modified date of a web page
Many web pages that do not list the last date and time they updated, modified, or changed. This information can be determined by using one of the suggestions in the following sections.
Although this site will not give you an exact modified date, it should give you a general idea. Also, it allows you to view the history of a page, even if it is offline. Visit the Internet Archive, and then enter the URL of the page in question into their search bar.