The IRS predicts that 8 million law-abiding procrastinators will let midnight April 16 slip by without completing their 2000 returns. Meanwhile, some 13 million taxpayers who make estimated quarterly payments to supplement withholding must begin that chore for this tax year based on a prediction of their tax bill. The deadline for most people this year is April 16 because the 15th falls on a Sunday. But residents of New England and upstate New York get until April 17 because the 16th is Patriots Day, which closes the facility in Massachusetts that handles their returns. A return postmarked on the due date is considered filed on time.
Many post offices stay open late to accept last-minute returns.
Those who file by computer are generally considered to have filed when they transmit the return. There's no penalty for filing late if you're due a refund. You can extend the filing deadline to August 15 just by asking. The usual way is to mail in Form 4868. There's also a penalty of 0.5 percent a month if the amount owed is more than 10 percent of your total tax.