You might recall that the gold model was in short supply prior to the launch of the iPhone 5s. Things got worst once the phone was officially launched and estimates for shipping the device in any of its three colors quickly reached 7 to 10 business days within hours of the phone's release. Eventually, lead times reached as high as 2 to 3 weeks before dropping back.
Apple has pumped up production of the Apple iPhone 5s, including a 33% hike in the gold colored model and cut back on building the slower selling Apple iPhone 5c. This has enabled Apple to build up enough stock of its full-featured phone for the holiday shopping season. In addition to online sales of the device, Apple has been whipping its elves hard to make sure the brick and mortar Apple Stores have enough inventory of the Apple iPhone 5s in all colors and capacities.
Apple has told those who want to order an Apple iPhone 5s for Christmas that the order must be received by midnight, December 12th, for it to arrive in time for the holiday.
source: MacRumors via BGR