Budget Gimmicks in a Trade Bill?

I fully admit that I'm not a tax/budget geek, but a tax provision slipped into a benign trade bill has set off my libertarian spidey-senses. BNA (subscription) explains:

Legislation (H.R. 4284) to extend the Generalized System of Preferences and the Andean Trade Preference Act, signed by the president Dec. 28, contains an offset that would increase 2014 estimated tax payments for corporations with at least $1 billion in assets in 2013.

The act (Pub. L. No. 111-124) increased by 1.5 percent the portion of corporate estimated tax payments due in July 2014 through September 2014.

It amended the Tax Increase Prevention and Reconciliation Act of 2005 to increase estimated tax payments for such corporations due in July, August, and September 2014 to 101.75 percent of what was otherwise due, according to the Congressional Research Service.

JCT estimated that the provision would increase revenues by $806 million in fiscal year 2014 and decrease revenues by $806 million in fiscal year 2015.

The measure passed the House Dec. 14 and the Senate Dec. 22, in both cases under a suspension of the rules by voice vote and unanimous consent, respectively.

The final law is here, and the legislative language is as follows:

SEC. 4. TIME FOR PAYMENT OF CORPORATE ESTIMATED TAXES.

The percentage under paragraph (1) of section 202(b) of the Corporate Estimated Tax Shift Act of 2009 in effect on the date of the enactment of this Act is increased by 1.5 percentage points.

The CBO scoring of the law is here. The CBO scoring matches the JCT estimate above, saying that this tax measure will goose federal revenues by $806 million in FY14, but immediately reduce them by the same amount in FY15.  So what gives?

I googled around and found only one analysis of the underlying "Corporate Estimated Tax Shift Act of 2009," from a random blog which calls the Act "good for the government, which extracts money from the business community sooner than planned."  So by increasing the percentages in the underlying Act, a random, non-germane provision of the GSP bill seems to extract even more money from big business "sooner than planned."

But why?  Normally, I'd just blow this minutia off, but considering the ridiculous budget gimmicks that the 111th Congress has attempted to pull off in order to secure its overreaching agenda, I'm calling "shenanigans."  So, any tax/budget specialists out there care to opine as to why the government is trying to squeeze out an extra 800 million at the end of FY14 instead of letting it go as planned into FY15?