WWW [Fox News] – Britney Spears didn’t pick Nov. 6 as the day to file for divorce from Kevin Federline by accident.

She filed two years and one month from the day of her marriage, on Oct. 6, 2004. Her prenup, according to legal theorists, evidently carried increases for Federline for every year of their marriage. And those deadlines, they say, likely had 30-day grace periods.

Hence, Nov. 6 would have been Britney’s last chance to get out of paying a third year of alimony settlement to a basically talentless slacker who was a drain on her finances.

And in the end, money is probably what Spears’ divorce is all about. Since she deliberately showed off a new trim body on David Letterman’s show the other night, Spears is obviously getting ready to go back to work. If a new album and tour are on the boards, Spears obviously doesn’t want to share the proceeds with Federline. It was clearly better to get out now, so that K-Fed can lay claim to only half of Spears’ earnings during what has been the most fallow period in her career.

Indeed, Spears has no doubt been feeling the pinch of diminished income since she met Federline and quickly had two children with him. The one thing she’s been unable to do is tour, and that’s really where she makes her bread and butter.

Spears has never been a huge recording artist. She hasn’t released an album of new material since 2003, and it’s hard to say whether there’s an audience out there to buy a new album.

Her biggest hits occurred some time ago, between 1999 and 2001, when “Baby One More Time” and “Oops I Did It Again” caused sensations. But Spears didn’t write those songs, and she doesn’t get a publishing royalty for any of her few big hits. That has no doubt hurt her pocketbook, since sales of her albums are long since finished.

Without touring, and getting paid for commercial endorsements, Spears doesn’t have much of a profitable career these days. Add in two kids, a husband with expensive tastes who doesn’t earn money, various family members and employees, and Spears could be facing Michael Jackson type financial problems. Offloading Federline, even with a prenup, is probably the first best thing she can do to cut expenses.

Spears, by the way, also has her name on a charitable foundation. But Nina Biggar, director of the Cambridge, Mass.-based Britney Spears Foundation, didn’t even know Spears had filed for divorce when I called her yesterday. She told me that the organization had given away almost $2 million in its short life, including $800,000 to the Twin Towers Fund.

The charity is entirely funded by Spears, but Biggar told me that this past year’s contribution was lower than the one before. This doesn’t reflect lack of interest on Spears’ part, but just lack of funds. Once K-Fed is off the payroll, Britney will be able to afford a return to her charitable activities.