Re: [LEAPSECS] Leap seconds ain't broken, but most implementations are broken

2017-01-06 Thread Hal Murray
leapsecs-requ...@leapsecond.com said: > Right, that's where I say its incredible nothing was done since 1972. The > Leap Second history is fundamental, and it seems to me an obvious missing > link. How could it have gone ignored all this time? Back in the old days, computer clocks weren't

Re: [LEAPSECS] alternative to smearing

2017-01-06 Thread Hal Murray
>> Are there any performance critical chunks of code that want to wait until N >> years from now? I doubt it. > With due respect, that's a crappy attitude to getting something right. You > want to have one interface that always works that's easy to use and schedule > with. If you don't have

Re: [LEAPSECS] Leap seconds ain't broken, but most implementations are broken

2017-01-06 Thread Brooks Harris
On 2017-01-06 11:33 AM, Martin Burnicki wrote: Brooks Harris wrote: On 2017-01-05 05:56 AM, Tony Finch wrote: Martin Burnicki wrote: Please note that NTP servers not necessarily need to be providers for leap second files. There are some well known sites which

Re: [LEAPSECS] Leap seconds ain't broken, but most implementations are broken

2017-01-06 Thread Zefram
Brooks Harris wrote: >It is often repeated on LEAPSECS that "Windows doesn't even know leap >seconds". That's just not true. It knows very well about Leap Seconds in the >same way other systems do but it (typical desktop versions) is lazy about >when it updates No, what it does doesn't involve

Re: [LEAPSECS] Time math libraries, UTC to TAI

2017-01-06 Thread Brooks Harris
On 2017-01-06 02:56 PM, Warner Losh wrote: Keep in mind that leap seconds have a short shelf life. Over the next 1000 years, it's projected TAI - UT will grow to about an hour (2500-4500 if I'm reading https://www.ucolick.org/~sla/leapsecs/deltat.html right). I dare say everybody on LEAPSECS

Re: [LEAPSECS] Time math libraries, UTC to TAI

2017-01-06 Thread Warner Losh
Keep in mind that leap seconds have a short shelf life. Over the next 1000 years, it's projected TAI - UT will grow to about an hour (2500-4500 if I'm reading https://www.ucolick.org/~sla/leapsecs/deltat.html right). In two thousand it will be about 4 hours due to quadratic acceleration. That's

Re: [LEAPSECS] Time math libraries, UTC to TAI

2017-01-06 Thread GERRY ASHTON
The Gregorian calendar and UTC with leap seconds are in harmony; the customary change-of-day time with the Gregorian calendar is midnight, and the methods used to establish midnight throughout most of the time the Gregorian calendar has been in use did not approach accuracy of tens of seconds.

Re: [LEAPSECS] Leap seconds ain't broken, but most implementations are broken

2017-01-06 Thread Martin Burnicki
Steffen Nurpmeso wrote: > Martin Burnicki wrote: > |Yes, and there needs to be an interface to timekeeping software in > |general, i.e. provide glibc and friends with updated tz rules, and make > |the leapsecond table available in a form that can be used by ntpd

Re: [LEAPSECS] Time math libraries, UTC to TAI

2017-01-06 Thread Brooks Harris
On 2017-01-05 09:33 PM, Steve Summit wrote: Brooks Harris wrote: It seems to me infeasible to alter the basic behavior of time_t because it effects every aspect of the operating system, Absolutely. Posix time_t is untouchable, and here to stay. POSIX time and 86400-second-day systems

Re: [LEAPSECS] Leap seconds ain't broken, but most implementations are broken

2017-01-06 Thread Martin Burnicki
Brooks Harris wrote: > On 2017-01-05 05:56 AM, Tony Finch wrote: >> Martin Burnicki wrote: >>> Please note that NTP servers not necessarily need to be providers for >>> leap second files. There are some well known sites which provide this >>> file, and the NTP

Re: [LEAPSECS] Time math libraries, UTC to TAI

2017-01-06 Thread Martin Burnicki
Steve Summit wrote (offlist): > In some ways I agree that running the kernel on TAI would be far > preferable. I've shied away from it so as to be able to answer > the critics who are always worrying about disconnected systems > that might not have a source of TAI-UTC at boot time, or at all. If

Re: [LEAPSECS] Time math libraries, UTC to TAI

2017-01-06 Thread Zefram
Steve Summit wrote: >I have implemented gmtime_ts_r() and mktime_ts() >which operate on struct timespec, and do the right thing with :60. Have you also extended struct tm to include tm_nsec? >I'm not ready to think about the filesystem yet (beyond thinking >that leapsecond-aware