On June 18, Mark Zuckerberg updated his cover photo for the first time. Funny thing is, cover photos weren't officially unveiled until Sept. 22, when Zuckerberg debuted them as a key feature of Facebook's new Timeline profiles at the f8 developer conference in San Francisco.

More than 800 million Facebook users patiently wait for the Timeline redesign, thanks to an untimely legal battle over domain names, but it's possible that Zuckerberg has been using Timeline since mid-June, at the very least.

The Timeline, for those who don't know what's coming, is a completely redesigned Facebook profile, where all of your information is arranged to look like a digital scrapbook of your life. Don Draper explains it best.

The centerpiece of Timeline is the cover photo, which appears as a banner photo directly above your profile, and also shares screen time with your traditional profile picture. All cover photos you upload go into an album, but unlike other photo albums on Facebook, any user can see another user's cover photo album regardless of privacy settings. This is why Zuckerberg's history of cover photo uploads is completely open to the public. However, you need to be running a beta version of Facebook Timeline yourself to see it. Upgrade to Facebook Timeline right now and see for yourself.

Zuckerberg uploaded his first-ever cover photo on June 18, and he also uploaded two other cover photos that same day. No surprise, all three photos were of his fluffy white dog, Beast. If June 18 was the first day Zuckerberg ran a near-complete version of Timeline on his own profile, it would make sense that Zuckerberg uploaded multiple cover photos. The cover photo is, after all, the focal point of the new profiles, and most users will immediately obsess and experiment with finding the perfect cover photo right out of the gate.

Since the cover photo shows up in Zuckerberg's Timeline of events, cover photos were a working and functional part of his profile since June. Therefore, one may conclude that June 18 was Zuckerberg's maiden voyage on a near-complete version of the Facebook Timeline profiles.

It's also possible that Zuckerberg was working on a very early version of the Timeline profile, or that he had the cover photo functionality before he had the full Timeline.

If Zuckerberg uploaded his first functional cover photo on his fIf June 18, this could have been also potentially been Zuckerberg's inaugural trip on the new-look profile.

A week before Zuckerberg uploaded his first Cover Photo, a report surfaced that Facebook was developing an iPad app. This aligns with an earlier report from Jeff Verkoeyen, a former Facebook employee and lead developer on Facebook's iPad app, who claimed that Facebook was sitting on a finished product and refused to release it. Sources say Facebook will finally announce its completed iPad app at Apple's Let's Talk iPhone event Tuesday in Cupertino, Calif.

Besides Zuck, no other major players at Facebook uploaded their first cover photo as early as June. A few developers uploaded their first cover photos on Sept 22., the day Timeline debuted at f8, but the vast majority of Facebook's engineers, developers, and executives currently with profiles were not using it prior to September. Therefore, it's possible that Zuckerberg was developing and implementing Timeline on his own profile long before anyone else at his company.

Representatives from Facebook in Palo Alto, Calif., declined to comment.