Disaster Tax Relief Act of 2020 This bill sets forth tax relief provisions for individual and business taxpayers residing in a disaster zone during the period beginning on July 1, 2020, and ending 60 days after the enactment of this bill. Specifically, the bill allows penalty-free disaster-relief withdrawals from tax-exempt retirement plans up to $100,000, permits recontributions of such withdrawals for home purchases cancelled due to disasters, increases to $100,000 the limit on loans for disaster assistance from retirement plans, allows employers affected by a disaster a 40% tax credit for the purpose of retaining employees, increases the tax deduction for corporate disaster relief contributions, enhances the tax deduction for disaster-related personal casualty losses, permits the calculation of the earned income tax credit based upon income earned prior to 2020, and reimburses U.S. possessions for losses sustained due to the application of the provisions of this bill.