[Clodfobble]

I was about to ask, but then found the answer in the article:

The target year for the crypt's future opening– 8113 A.D.– was arrived at by considering 1936 to be the halfway point to the future. 6,177 years had passed since the Egyptian calendar had been established in 4241 B.C., so Dr. Jacobs projected forward the same number of years from the date of his idea's birth.

Another very (I mean damn) interesting bit:

In the event that the Crypt of Civilization is opened by people who do not speak English as we know it, the room includes numerous pictographic representations of information, perhaps the most important of which describing the operation of the vault's "language integrator"– the first piece of technology that one should encounter upon entering this technology tomb. Ironically, it seems that much of the information regarding this machine has been lost to the eroding effects of time, but it is said that this hand-powered English-teaching device was inspired by the Rosetta stone, yet based on the "Nickelodeon principle." It's vocabulary consists of only 1,500 words, a subset of our language called "Basic English" which was used in cryptographic codes in the first World War.