The fiscal year of 1399 for all those taxpayers who uses solar calendar, is ended on the date (30/12/1399 = 20 March 2021), and for all those taxpayers who use Gregorian calendar, the final date for submitting the annual income tax returns will be (11/01/1400 = March 21 2021); based on the tax laws, all the taxpayers are liable to submit their 1399 annual income tax returns, and should pay all their tax liabilities before the above mentioned date, otherwise according to tax laws enforcement actions will be taken.