BIPM Votes to Retire Leap Second by May 20, 2027
The International Bureau of Weights and Measures will replace the leap second with a leap hour, advancing the change from 2035.
The International Bureau of Weights and Measures (BIPM) has voted to retire the leap second and replace it with a leap hour, moving the change forward from 2035 to May 20, 2027, according to tomshardware.com.
The BIPM said a negative leap second has never been applied and is considered high risk for critical infrastructure. Preparing for one would require investment similar to millennium bug preparations, the organization estimated.
The agency said the change would keep Coordinated Universal Time (UTC) in sync with TAI for several centuries. It also noted that hour-sized time changes already occur through time zones and daylight-saving time.
Leap seconds have caused disruption before: clocks showed 23:59:60 on Dec. 31, 2016, before switching to 00:00:00 on Jan. 1, 2017, and Reddit crashed after a leap second was added in 2012.
According to the BIPM, there was a 30% probability of needing a negative leap second by 2035.
Quick answers
When will the leap second be retired?
On May 20, 2027, under the BIPM's revised plan, which moves the change forward from 2035.
What will replace the leap second?
A leap hour, which the BIPM says will keep UTC in sync with TAI for several centuries.
Why is the BIPM making the change?
The BIPM said a negative leap second has never been applied and is considered high risk for critical infrastructure.