The brilliant scientists created an optical clock that changes by one second every seven billion years.
As a result, we are getting much closer to redefining the second as the fundamental unit of time.
China is now the second country in the world to attain such exact timekeeping, which is an extraordinary accomplishment.
Physicist Pan Jianwei headed the team that published their findings this past month in the peer-reviewed journal Metrologia.
They said that the device opens the door for the creation of an international network of optical clocks.