April 15 typically marks the IRS tax day, but like last year, the tax filing deadline won’t fall on the date. Emancipation Day is April 16, a holiday commemorating when President Abraham Lincoln signed the District of Columbia Compensated Emancipation Act into effect in 1862.

Since April 16 is a Saturday, the holiday will be observed on Friday, April 15. Hence, this year’s tax day will be on Monday, April 18 for most of the U.S.