A "Tax Year" refers to the annual period for which tax returns are prepared and filed. In many countries, including the United States, the tax year typically runs from January 1 to December 31. This period is used by individuals and businesses to calculate their income, expenses, and tax obligations. At the end of the tax year, taxpayers must report their earnings and pay any taxes owed to the government. The information is submitted using forms such as the IRS Form 1040 for individuals. Understanding the tax year is essential for compliance with tax laws and for effective financial planning.