The bill allows the IRS to postpone tax deadlines for up to 120 days in the event of a state-declared disaster. It grants authority to governors and mayors to request these postponements by consulting the Federal Emergency Management Agency. These extensions apply to various natural catastrophes, fires, floods, and explosions, and would also cover the District of Columbia and U.S. territories. The bill extends the previous 60-day mandatory extensions to 120 days. These changes will apply to disaster declarations made after the bill's enactment.