WASHINGTON >> Taxpayers will get an extra three days to file their federal tax returns this year, and they can thank the nation’s capital for the extra time.

The filing deadline is delayed because the District of Columbia will observe Emancipation Day on Friday, April 15. By law, local holidays in the nation’s capital impact tax deadlines the same way federal holidays would, the Internal Revenue Service said.

Taxpayers will have until midnight Monday, April 18, to file their 2010 returns. Taxpayers requesting an extension will have until Oct. 17 to file their returns.

Emancipation Day marks the occasion when President Abraham Lincoln signed into law a bill ending slavery in the District of Columbia. Lincoln signed the bill on April 16, 1862, more than eight months before he signed the Emancipation Proclamation, which eventually led to all slaves being freed.

The IRS expects to process more than 140 million individual tax returns this year. Most taxpayers can fill out their returns and file them as soon as they receive all their tax documents from employers, banks and other financial institutions. Some taxpayers, however, will have to wait to file until mid- to late February to file their returns because of late changes to the 2010 tax law passed by Congress in December.

The IRS said it needs more time to re-program its processing systems to take into account the new law. The agency plans to announce a more definitive filing date before then.

Those who must wait to file include people who itemize their deductions, taxpayers who claim a deduction for college tuition and fees, and school teachers who claim a deduction for out-of-pocket classroom expenses.