Tax Day 2015: 10 Things You Didn't Know About Dreaded Date

The most dreadful day of the year is here: Tax Day. That means the deadline for filing federal income tax returns has come.

Income tax was first introduced in the United States of America in 1861. In 1913 Tax Day, or the filing deadline, was fixed on March 1. However, it was moved to March 15 in 1918 and April 15 in 1955, where it has remained since then.

Returns must be properly addressed and postmarked no later than Wednesday or they are considered late. You should try to file your full return, but you can also file for an extension. If you can't pay the full amount, the IRS will work with you.

If you haven't filed your income tax return yet, you still have time to do so!

Here are 10 things you probably didn’t know about Tax Day:

1) If April 15 falls on a Saturday, Sunday or a civil holiday, the deadline is extended to the next working day.

2) 28 minutes: The average wait time when calling the IRS (compared with 11 minutes in 2010).

3) 7 weeks: estimated timetable for refunds (normally, it's 4-6 weeks).

4) Chances of getting audited are slim.

5) 6 million households are expected to pay an Obamacare penalty for not obtaining insurance.

6) The total U.S. tax bill (including federal, state, and local) is $4.8 trillion.

7) The average tax refund is $3,120.

8) There are 4 million words in the U.S. tax code. That's 5x the words in the Bible and 4x all of the Harry Potter books combined.

9) The total U.S. tax bill (including federal, state, and local) is $4.8 trillion.

10) There’s a bright side to Tax Day: Freebies! Many businesses give out free items to brighten people’s days.