We all know what today is -- it's the deadline for filing your tax return to the IRS. Did you ever wonder why April 15 was chosen as "tax day"? Way back on Feb. 3, 1913, Congress passed the 16th Amendment, which created our income tax requirement. Along with the legislation came a deadline for paying those taxes; Congress gave taxpayers a year plus six weeks as the very first deadline. The Revenue Act of 1918 pushed the date forward a bit more to March 15. And then in 1955, additional tax-code revisions moved the date a month further, to April 15.