The 21.5-inch model will be available on that date, while the 27-inch model will begin shipping in December.
The latest versions of Apple's iMac go on sale this Friday.
Apple said this morning that the 21.5-inch iMac will be available at that time through its online and retail stores and via some Apple resellers. The 27-inch iMac, meanwhile, will be available for order through the Apple Online Store and will begin shipping in December.
The 2012 edition of the iMac desktops come with 8GB of memory, a 1-terabyte hard drive, a quad-core Intel Core i5 processor, Nvidia GeForce graphics processors, and the new Fusion Drive, a hybrid that combines solid-state storage with a traditional platter-based hard drive.
The 21.5-inch model starts at $1,299, and the 27-inch model starts at $1,799.
Apple unveiled the iMacs in October at the same event that introduced the iPad Mini and the fourth-generation iPad. In his first take on the new iMac models, CNET's Rich Brown wrote:
In person, you can see that the design is amazingly thin at the edges, although it tapers out to a thicker portion at the back of the system. From the front it looks about the same as the earlier iMacs, chin included. Aesthetically, Apple leads the pack here as usual. In terms of functionality, other than the Thunderbolt port, there's not too much going on here that you can't also find in a well-equipped Windows all-in-one like the Dell XPS One 27.