April 15 is the day for reporting your income tax. This is true for at least for people living in US and Singapore. Singapore has quite low income tax and tax will not be withheld first when you get your pay check. Tax is much higher in US. Federal tax, state tax, property tax, social security tax, medicare tax should add up to more than 30 percent of salary. This year, April 11 is the official US tax freedom, which is the day Americans have finally earned enough money to pay off their total tax bill for the year. But for Washington state, tax freedom is April 15, 4 days late than national average.
To read more about tax freedom day: http://www.taxfoundation.org/taxfreedomday.html