(Credit: Screenshot by Lance Whitney/CNET)

Those of you ready to order a new 27-inch iMac will have to wait till next month for it to arrive.

Apple's latest estimate calls for a ship time of three to four weeks, zeroing in around early to mid-February. In early December, Apple offered a vague time frame of January. So people who ordered at that time hopefully will receive their computers by the end of the month.

The new 21.5-inch and 27-inch iMacs popped up for sale at Apple's Web site on November 30. The 27-incher offered an initial ship time of two to three weeks, but that jumped to three to four weeks after just a few hours.

At Apple's fourth-quarter earnings call on October 25, CEO Tim Cook cautioned that supplies of the iMac would be "constrained" the rest of 2012, leading to a "significant shortage."

Consumers eyeing the the 21.5-inch model face a wait time of 7 to 10 business days.