Everyone from Mashable to The White House is wishing Twitter a happy sixth birthday today, but we remember celebrating Twitter's birthday last July, too. So, what gives? 

The way the world works, everyone -- even websites -- get just one birthday per year. This is birthday fraud. From now on, Twitter, like the rest of us, gets just one special day. And, after taking a closer look into the history of Twitter and the definition of birthday's, we've decided to revoke Twitter's birthday boy status today. From this point forward: July 15 and not March 21 is Twitter's real birthday.

Today we are not celebrating Twitter's birth, but rather founder Jack Dorsey's first tweet:

Sure, this is cause for celebration. But only in the same way as a baby's first kicks in the womb are exciting. At the moment of that tweet (or twt?), Twitter was just a fetus of a site. Its parents, Jack Dorsey, Noah Glass, Evan Williams and Biz Stone, were thinking about what Twitter might look and act like when it made its public debut. They hadn't even settled on the name yet.  

Twitter didn't pop out of the womb, or "become born" until July 15, 2006, with the public launch of the site. Stone made the announcement on his personal site. And Twitter, "a new mobile service that helps groups of friends bounce random thoughts around with SMS" entered the world.

Even Twitter agrees with us on this birthday date. On that day last year it sent out a bunch of celebratory tweets. Today: Silence. Though, the social media site probably doesn't want to give up its second birthday -- it is great PR after-all. And with hundreds of "happy birthday" tweets, it doesn't look like the celebration will end until the day does.