Leap seconds can make time go both ways, but adding them makes time stop/go back because 24:00:00 cannot be represented as 1/86400 part of day N instead of day N+1 on major OSes. And they were only added so far.

[–] [email protected] 1 points 8 months ago* (last edited 8 months ago) (1 children)

It doesn't work like that. UTC goes forward always. Leap seconds are scheduled and known in advance. NTP time services will just smear time advancement a little to account for an additional second. Time never has to go backwards. This is how Google does it.

[–] [email protected] 1 points 8 months ago

This is how Google does it in their datacenters, but not major OSes by default