Mark, Mark Newman wrote: > Unruh - thanks for responding. You are the only one > who did. > > I certainly did not mean to disparage NTP time. I > have spec'ed that it be used on our system. Where I > run into problems is when a leap second occurs. > According to everything I've read when NTP signals > the operating system that the second is occurring it > also outputs time. It uses the POSIX standard method > - duplicate a second (or in some cases stretch the > last second). This causes confusion when a time > sample is taken before the leap second and one during > the leap second. The UTC standard (which only > addresses ascii time representations) actually counts > the second 0..60 rather than 0..59.
If you "normalize" the time with second 60 then you see there _is_ a duplicate time stamp. This is because a leap second _is_ a inconsistency of time. > At this point I am obligated to use UTC and NTP. On most Unix-like kernels NTP just passes a leap second announcement to the OS kernel, and the kernel handles the leap second in the way it is implemented in the kernel. For details, please see http://www.meinberg.de/english/info/leap-second.htm Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
