What a difference six days makes.

The Walton family, which founded Wal-Mart, could save as much as $180 million in federal income taxes after the huge retailer announced Monday that it would pay out its quarterly dividend on Dec. 27 instead of Jan. 2, as was scheduled.

The change will allow the family and other Wal-Mart shareholders to record the income this year, when the federal tax rate on dividends tops out at 15 percent. Next year, if the Obama administration and Republicans are unable to reach a compromise, that rate is set to jump sharply to 39.6 percent. High earners will have to pay an additional 3.8 percent on most investment income to help pay for the new federal health care law, bringing the total possible tax bite to 43.4 percent.

Wal-Mart is the biggest company to accelerate its dividend payments this year in anticipation of higher taxes next year, following such manufacturing companies as Leggett & Platt and Myers Industries.

Even if a compromise is reached and taxes do not rise quite as high as scheduled next year, investors and companies of all sorts appear to be betting that tax rates will be higher next year.