TAI offset is incorrect during the leap second

Solution Unverified - Updated -


  • TAI offset is incorrect during the leap second.
  • When repeating a UTC time value during a leap second (when the UTC time should be 23:59:60), the TAI timescale should not stop. The kernel NTP code increments the TAI offset one second too late.


  • Red Hat Enterprise Linux 6
  • Applications using TAI offset (specifically the tai field in the timex struct) on a system synchronized by NTP or PTP). This setting is not set system-wide, instead an application can make adjtimex() system calls to obtain the offset between TAI and UTC, which is where this issue exists.

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