45 / 180 Day Calculator the below 1031 calculator will help you figure out the crucial deadlines in your 1031 exchange. JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember 12345678910111213141516171819202122232425262728293031 2016201720182019202020212022 Initial sale date: 45 day identification period ends: 180 day purchase date ends: