The IRS will begin to accept/reject returns on January 29.
The IRS will not start officially accepting 2024 federal tax returns until January 27, 2025.
https://www.irs.gov/newsroom/irs-announces-jan-27-start-to-2025-tax-filing-season-agency-continues-historic-improvements-to-expand-enhance-tools-and-filing-options-to-help-taxpayers
IRS announces Jan. 27 start to 2025 tax filing season