45 / 180 Day Calculator Plug in your relinquished property sale date and determine your 45 day and 180 day 1031 exchange deadlines with this calculator. JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember 12345678910111213141516171819202122232425262728293031 2016201720182019202020212022 Initial sale date: 45 day identification period ends: 180 day purchase date ends: