When Are 2017 Taxes Due in 2018? How to File on Time, Request an Extension

This year's tax filing deadline is April 17, two days after the usual date of April 15 because that falls on a Sunday and the following day is Emancipation Day, a Washington, D.C. holiday. The taxes being paid in 2018 reflect 2017 income and deductions.

Only 34 percent of 1,000 millennials in America surveyed by H&R Block got the deadline correct when presented with three date options.

Related: Trump Tax Plan: 75 Percent of Americans Think the Wealthiest Should Pay More, Poll Shows

The Internal Revenue Service (IRS) has several electronic filing options for individual taxpayers: Free File forms, free tax return preparation sites, commercial software, and tax preparation professionals who are authorized e-file providers. Individuals who choose to e-file typically receive their tax refund within three weeks of the IRS receiving it, and sooner if they elect to have a bank direct deposit.

Individuals can also mail a paper Form 1040, postmarked by April 17. A tax return can take six to eight weeks to process if mailed.

"Paying someone to do them for you can be a good way to relieve some headache, and according to the survey, a third of Millennials already know this," Meg Sutton, director with H&R Block, said in a statement.

Those who are unable to make the April 17 deadline can file for an extension by the end of the day by completing the federal Form 4868 and mailing it postmarked, or online using Free File. That buys six months for a new deadline of October 15, before late-filing penalties are assessed. About 10 million taxpayers are expected to file for an extension, according to Forbes.

April 17 is also the final day to make a contribution to a traditional Individual Retirement Account (IRA) or Roth IRA. It is also the deadline for people who are self-employed or freelancers.

The GOP tax bill that President Donald Trump signed into law last December won't affect tax returns this year because this filing pertains to 2017. The tax bill went into effect in January of this year, and will affect tax returns in April 2019.