Every Facebook page has metadata attached to it, which developers can access to pull out specific details regarding that page. Unfortunately, a Facebook page's creation date is not part of its available metadata, so there is no foolproof way to locate an official creation date. If an approximate creation date works for your needs, or if you don't mind arriving at a reasonable guess, there are a couple of ways you can indirectly determine when a page first opened for business.
Load the Facebook page in question in your Web browser.
Click on the profile image to view the album of previous profile photos.
Click on the oldest profile photo. Its creation date likely coincides with the creation date of the Facebook page itself, though there is a chance the true original profile photo has since been deleted.
Scroll back through all the wall updates on the page until you find the very first update. This is a slower process than looking at the first profile picture, but can increase your confidence in the profile picture date if the first wall update also posted on that date.
Load the Facebook page in question in your Web browser.
Click on the profile image to view the album of previous profile photos.
Click on the oldest profile photo. Its creation date likely coincides with the creation date of the Facebook page itself, though there is a chance the true original profile photo has since been deleted.
Scroll back through all the wall updates on the page until you find the very first update. This is a slower process than looking at the first profile picture, but can increase your confidence in the profile picture date if the first wall update also posted on that date.