Was on the DFAS military pay site and found this
A change in the law means you’ll receive your September and December pay a few days earlier this year.
The 2011 National Defense Authorization Act requires DFAS to process your pay by the first day of the month. When that day falls on a weekend or national holiday, the pay date is moved to the previous business day.
In 2011, this means your payment normally scheduled for Oct. 3 will be issued on Sept. 30 and your payment normally scheduled for Jan. 3, 2012, will be issued on Dec. 30, 2011.
As a result of the second payment in December, you’ll receive a total of 13 pay checks instead of the normal 12 in the 2011 tax year, which may increase your tax liability.
Because Jan. 1 is always a federal holiday, going forward you’ll always receive your January pay the previous December. So in 2012 and beyond, when we’ve fully transitioned to the new schedule, you will receive the normal 12 pay checks.
See 2011 and 2012 Pay Schedule
This change applies to retired pay, Concurrent Retirement and Disability Pay, Combat Related Special Compensation, allotments, garnishments and court-ordered former spouse and child support payments. It does not affect annuity payments.
We cannot provide tax advice, but we encourage you to speak with a tax advisor, the Internal Revenue Service or your state tax authority to determine if your tax withholding will satisfy your federal and state income taxes when you file your 2011 tax return.
So be prepared for tax time. They have you coming and going