Definition of Assessment year :

Assessment year : – The term has been defined under section 2(9). This means a period of 12 months commencing on 1st April every year. The year in which tax is paid is called the assessment year while the year in respect of the income of which the tax is levied is called the previous year. For example, for the assessment year 2016-17, the relevant previous year is 2015-16 (1.4.2015 to 31.3.2016).