Oct. 12 has been predicted to be the date for the birth of a baby that will push the world’s population to 6 billion.

The new benchmark comes 12 years after the last billion.  It took 13 years for the billion before that. The U.N. is looking for slower growth over the next century, but some demographers now think the 7 billion mark could come even more quickly.

Median U.N. projections say it will take 14 years to add another billion people. Population projections, however, have become more complex than ever, with birth and death rates varying widely from region to region, the impact of AIDS, advances in population programs and   longer life expectancies. And there is of course 2012.