Look at your calendars people.
December 1st was on a Tuesday.
The first week of December doesn’t start on a Sunday.
It will be released on the week of the 15th (Tuesday) December 2015
If you still don’t see it. An example if you will.
If you get paid on Mondays. The first week you get paid on in December is on the second week yet first Monday of December. (The week of the 7th)