Every year since 1955, taxes have been due on April 15 ... except for sometimes. Like the last two years. And this year.
Tax Day falls on Tuesday, April 17 for 2018.
That's the deadline for filing your 2017 federal tax return, the last day to make a contribution to an individual retirement account for it to count against 2017 income, the deadline to file a tax extension, and the day when quarterly estimated tax payments are due for those who make them.
This short reprieve appears to be a good thing: As of April 13, the IRS was still waiting on as many as 40 million taxpayers to file their returns.
So why is Tax Day on April 17 this year? Basically, it's due to a combination of the 15th falling on a Sunday and a holiday unique to Washington, D.C., hitting on Monday the 16th.
The nation's capital celebrates Emancipation Day to mark the date that President Abraham Lincoln freed slaves there in 1862. While it's a local holiday, it affects when taxes are due.
Last year, Tax Day was even later due to similar circumstances: the 15th was on a Saturday and Emancipation Day was celebrated on Monday the 17th. So taxes last year were due April 18.
The changing dates could be especially confusing for newer taxpayers.
A recent survey by H&R Block showed that 66 percent of millennials did not know taxes are due this year on the 17th, even though they were given three dates to choose from.
In 2019, Tax Day will return to the usual April 15 and will stay there until the calendar works in your favor again and gives you a few extra days to get your taxes done.
This story is part of CNBC's Tax Week coverage as the filing season wraps up on April 17. Stay tuned for more stories on tax tips and savings opportunities.
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If you can't pay what you owe the IRS by Tax Day, here's what to do
