0001845337 2026-04-22 2026-04-22 --12-31 false 0001845337 8-K 2026-04-22 DAY ONE BIOPHARMACEUTICALS, INC. DE 001-40431 83-2415215 1800 Sierra Point Parkway Suite 200 Brisbane CA 94005 650 484-0899 false false false false Common Stock, par value $0.0001 per share DAWN NASDAQ false