We report on the first timescale based entirely on optical technology. Existing timescales, including those incorporating optical frequency standards, rely exclusively on microwave local oscillators owing to the lack of an optical oscillator with the required frequency predictability and stability for reliable steering. We combine a cryogenic silicon cavity exhibiting improved long-term stability and an accurate lattice clock to form a timescale that outperforms them all. Our timescale accumulates an estimated time error of only over 34 days of operation. Our analysis indicates that this timescale is capable of reaching a stability below after a few months of averaging, making timekeeping at the level a realistic prospect.