WASHINGTON — The Internal Revenue Service made it a little easier to procrastinate this year. Not only do taxpayers have two or three extra days to file, but they also can ask for the first time for an automatic six-month extension.

Nearly 88 million taxpayers have filed their returns, but that leaves millions more working to meet the deadline — Monday for most people.

The IRS expects 9.6 million to miss the mark in April and request an automatic filing extension until Oct. 16. But they have to pay their taxes now.

"Most people do leave it to the end for good reason. It's not an enjoyable thing to do," said Eric Tyson, author of "Taxes 2006 for Dummies."

"If you have the choice between enjoying the weather and doing your tax return, it's not a hard choice," Tyson said.

IRS officials are encouraging people who are worried about the approaching deadline to consider filing for an automatic extension. The extension now is for six months, compared with four months offered in years past.

"For people who haven't yet prepared their returns, the first thing they should do is don't panic," said the agency's commissioner, Mark Everson.

The deadline for requesting an automatic extension is the same as the tax filing deadline. The IRS this year gave taxpayers an extra weekend to finish their work because April 15 falls on a Saturday. The tax agency pushed the traditional deadline back to April 17 for most taxpayers.

People whose returns go to a processing center in Massachusetts have one additional day because of Patriots Day. That holiday means residents of Maine, Maryland, Massachusetts, New Hampshire, New York, Vermont and the District of Columbia have until Tuesday to file.

The IRS separately gave individuals and taxpayers in regions most severely damaged by Hurricane Katrina a filing deadline of Aug. 28. They can request an extension until Feb. 28, 2007, if they cannot file by August.

Taxpayers who file for an extension get more time to finish the paperwork, but not more time to pay their taxes. The simple form, which can be filed electronically, requires them to estimate and pay taxes they may owe.

Taxes not paid by the due date accumulate interest and late-payment penalties, but those can be considerably less than the late-filing penalties imposed on taxpayers who do not file their returns or ask for an extension.

People who plan to finish the forms in the last few days should make sure to set aside a block of time.

"The first and probably the most important thing is to not do a rush job and shortchange yourself," Tyson said.

Tax experts urge individuals to look at their possible deductions and consider whether they would be better off using the standard deduction or adding up their itemized deductions.

Taxpayers also have until the tax filing deadline to make 2005 contributions to some retirement accounts.

Everson also cautioned taxpayers not to let their panic tempt them into using a tax preparer without checking out the professional's background and reliability.