Guy, Guy Macon <http://www.guymacon.com/> wrote: > Martin Burnicki wrote: >>I'm pretty sure Dave Mills is correct. For an introduction of leap seconds >>and how they may be handled you migth have a look at >>http://www.meinberg.de/english/info/leap-second.htm#overview >> >>Search for "normalize" at the end of that section. > > I see that. Key phrase: > "2 consequent seconds have the same time stamp"
Isn't that true for counting seconds? 2005-12-31 23.59.60 <-- leap second 2006-01-01 00.00.00 We can normalize the time and date of the leap second: 60 seconds are 1 minute, which lets the minutes increment from 59 to 60 60 minutes are 1 hour, which lets the hours increment from 23 to 24 24 hours are 1 day, which lets the date increment, and so on. Finally we can say that both lines represent exactly the same time, or 2 consequent seconds have the same time stamp. > A post in the comp.protocols.time.ntp mailing list goes into > further detail: > > "every time a leap second happens, the fraction part > of the second, in the NTP timestamp keeps counting. That's > the fraction part only. It does not roll over to the next > second. Instead, the same second is repeated - thus we repeat > the same time, which means we go back in time. However, the > NTP timestamp sends out a leap second flag, which causes > your computer to go to the 61st second." > > http://mailgate.dada.net/comp/comp.protocols.time.ntp/msg08459.html > > It looks like we were both wrong. The NTP clock doesn't stop, as > David L. Mills wrote, nor does it continue into a 61st second, > which is what I thought it does. Instead it jumps back a second > and repeats the 60th second with a leap second flag set. No, at least I'm not wrong. Did you also have a look at the rest of the page I've mentioned? You must distinguish between how a leap second is defined in civil time, and how it is handled by different implementations like operating systems, or NTP. See the chapter "Operating Systems": http://www.meinberg.de/english/info/leap-second.htm#os Did you also have a look at Dave Mills' reply to that news article you've quoted above, and the link Dave has posted? http://www.eecis.udel.edu/~mills/leap.html Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
