The Internet celebrates its 42nd birthday today, putting it on the cusp of middle age and making its sign an Aries, which is "masculine" and extroverted, says the Internet. But maybe it was actually born in September? Or October? Is it even 42? Some people swear the Internet doesn't look a day over 28. Here are some the leading claims for days the Internet was born.

April 7 , 1969

The first Request for Comment document is drafted by an engineer on the Pentagon's ARPAnet project, a precursor to the modern Internet.  Tony Long of Wired argues this represents the "symbolic birth date of the net because the RFC memoranda contain research, proposals and methodologies applicable to internet technology."

September 2, 1969

UCLA computer science professor Leonard Kleinrock establishes the first local connection between two computers in his lab. Matthew Moore of The Telegraph called this "the most appropriate" of all the anniversaries. Discovery magazine and National Geographic both identify this as the true date of birth.

October 29 1969

Kleinrock's computer at UCLA transmits the first host-to-host message to a machine at the Stanford Research Institute. Kleinrock, for his part, identifies this as the "first breath of life the Internet ever took." PC World's Jared Newman agrees "[If we can all agree that communication--e-mail, chat, social networking--is what makes the Internet tick," writes Newman, "Kleinrock's first message was the most significant early step towards what we have today.

January 1 , 1983

Wired's Justin Jaffe nominates the day the switch was made Network Control Protocol to Transmission Control Protocol and Internet Protocol as the real date to remember. "The transition from NCP to TCP/IP may not have been the sexiest moment in Internet history" he concedes, but notes the new protocol was needed to "accommodate the much larger and more complicated network [researchers] foresaw as the Internet's future."