On Jul 28, 2026, at 2:43 AM, Guy Harris <gharris@xxxxxxxxx> wrote:
> However, especially with modern UN*X systems providing POSIX time, in practice a lot of time stamps in packets, as well as the capture tie stamp, are in PT - POSIX Time - not UTC. Some UTC values have *no* corresponding PT values, so mapping PT values to UTC values gets tricky around the end of the days with green boxes in the table at https://en.wikipedia.org/wiki/Leap_second#Procedure.
BTW, look at the cheerful statement at the end of that section:
Recent changes to the Earth's rotation rate have made it more likely that a negative leap second will be required before the abolition of leap seconds in 2035.[33][34]
with reference 33 being https://web.archive.org/web/20250124104744/https://www.gps.gov/cgsic/meetings/2022/matsakis.pdf (the original link is dead, so I had to find that and fix it) and reference 34 being https://www.nature.com/articles/s41586-024-07170-0.
So we may not manage to avoid leap seconds in the time before we drive a stake through their heart *and* we may even get a never-seen-before *negative* leap second.