April 15 is the deadline for individuals in the United States to file their annual income tax returns with the Internal Revenue Service (IRS). This date marks the end of the tax year for most taxpayers, and it is when they must report their earnings and calculate any taxes owed or refunds due. If April 15 falls on a weekend or holiday, the deadline may be extended to the next business day. Taxpayers can file their returns electronically or by mail, and many choose to seek assistance from tax professionals or use tax preparation software to ensure accuracy.