Facebook develops super-precise public time-keeping service for the internet

The social network says it's improved the accuracy of time telling from 10 milliseconds to 100 microseconds.

Katie Collins Senior European Correspondent
Katie a UK-based news reporter and features writer. Officially, she is CNET's European correspondent, covering tech policy and Big Tech in the EU and UK. Unofficially, she serves as CNET's Taylor Swift correspondent. You can also find her writing about tech for good, ethics and human rights, the climate crisis, robots, travel and digital culture. She was once described a "living synth" by London's Evening Standard for having a microchip injected into her hand.
Katie Collins
2 min read

Facebook has been working to try to solve the problem of time inaccuracy.


Who keeps time on the internet? It's probably something you haven't much considered before. But every internet-connected device, of which there are billions, has an onboard clock, and not all of them are synced up to keep time precisely.

In everyday life, the focus of timekeeping tends to be on minutes rather than seconds, but an inaccuracy of a single second on the internet can cause issues such as missed reminders, or in serious cases, the delay of a spacecraft launch. Leap seconds, one-second adjustments occasionally applied to Coordinated Universal Time to accommodate the difference between precise time and imprecise observed solar time, can prove especially disruptive. But tech companies have workarounds.

Facebook published details on Wednesday of a new public time-keeping service that relies on combination of satellite data and its own servers. In a blog post, the company explained how the service has improved the accuracy of time telling from 10 milliseconds to 100 microseconds and verified the results in its laboratory.

"As Facebook's infrastructure has grown, time precision in our systems has become more and more important," the company said in the post, explaining why its engineering team has tackled this particular challenge. "We need to know the accurate time difference between two random servers in a data center so that datastore writes don't mix up the order of transactions. We need to sync all the servers across many data centers with sub-millisecond precision."

Internet-connected devices generally rely on syncing up with Network Time Protocol servers to stay on track with time. A number of sources already provide NTP servers that devices can connect to in order to ensure they're keeping accurate time, including Apple and Google. Facebook now has its own NTP server, which it compared with Apple and Google's NTP services as part of its testing. It concluded it was "competitive with other popular providers, but in some cases, it also outperforms them."

If you want to check out the service now and try it out by configuring it with your own device, you can find it at Time.facebook.com.