The National Institute of Standards and Technology (NIST) U.S. has set a new world record for the most accurate aluminum ion-based optical atomic clock.

This clock sets a new time-keeping benchmark, accurately measuring a second down to its 19th decimal place. That’s a major leap, making it 41% more accurate and 2.6 times more stable than the former record holder.

The aluminum ion clock’s accuracy record stems from two decades of persistent refinement.