0001845337 2022-01-05 2022-01-05 false 0001845337 8-K 2022-01-05 DAY ONE BIOPHARMACEUTICALS, INC. DE 001-40431 83-2415215 395 Oyster Point Blvd., Suite 217 South San Francisco CA 94080 (650) 484-0899 false false false false Common Stock, par value $0.0001 per share DAWN NASDAQ true false