Tax Day is the day that income taxes are due from most employed American citizens. Although income tax was first collected once during the American civil war,
it was not collected yearly until 1913 when the 16th Amendment was added to the Constitution giving Congress the legal authority to tax people's incomes.
It has been on April 15 but in the event that it falls on a weekend or holiday it moves to the next closest Monday or business day.
Tax Day 
