Here's a link to an article about the Hajj, the pilgrimage to Mecca which Muslims are expected to make at least once in their lifetime. It provides more information than what is generally reported. http://www.sun-sentinel.com/news/local/southflorida/sfl-flphajj1113pnnov13,0,201556.story.
Be advised that the 3 week period surrounding December 18 - 22 (dates of the Hajj) will be a period when thousands of U.S. Muslims will be traveling to Saudi Arabia. I have an acquaintance who is a commercial aviator.
He tells me that the logistics of moving some two million Muslims from all over the world to and from Mecca for the Hajj requires reactivating retired aircraft for all the special charter flights.
Those used to run charters from really backward third world nations will often be so fouled by the passengers....some of whom may have never used a flush toilet, that afterwards they are unfit for further passenger service. They will be stripped of seats and subsequently used only as air freighters.
Incidentally, this Hajj period may be a good time to stay away from crowded major malls. The absence of faithful Muslims just may provide a period during which terrorist attacks might be planned. Crowded malls have been identified as potential target sites.
This will be the first time in many years that the annual Hajj occurs during the Holiday shopping period. This happens due to the fact that Islam observes a twelve month calendar of 28 day lunar months, (336 days) so Hajj is 29 days earlier this year than last.