Re: Ambiguous NTP timestamps near leap second

2006-02-16 Thread Markus Kuhn
M. Warner Losh wrote on 2006-02-14 21:18 UTC: ntp time stampes are ambiguous at leap seconds (the leap indicator bits aren't part of the time stamp, exactly), which is a good reason to change them. However, the cost to change them could be quite high if done in an incompatible manner. No,

Re: Ambiguous NTP timestamps near leap second

2006-02-16 Thread Steve Allen
On Thu 2006-02-16T19:12:30 +, Markus Kuhn hath writ: No reply from an NTP server shall ever represent any point in time between 23:59:60 and 24:00:00 of a UTC day. If a client requests an NTP timestamp and the response would represent a point in time during an inserted leap second,

Re: Ambiguous NTP timestamps near leap second

2006-02-16 Thread Warner Losh
M. Warner Losh wrote on 2006-02-14 21:18 UTC: ntp time stampes are ambiguous at leap seconds (the leap indicator bits aren't part of the time stamp, exactly), which is a good reason to change them. However, the cost to change them could be quite high if done in an incompatible manner.

Re: 24:00 versus 00:00

2006-02-16 Thread Markus Kuhn
Steve Allen wrote on 2006-02-16 19:25 UTC: No reply from an NTP server shall ever represent any point in time between 23:59:60 and 24:00:00 of a UTC day. Minor point, I think it has to read more like this between 23:59:60 of a UTC day that ends with a positive leap

Re: Ambiguous NTP timestamps near leap second

2006-02-16 Thread Markus Kuhn
Rob Seaman wrote on 2006-02-16 20:28 UTC: In fact, to simplify coding, simply reject all requests received between 23:59:00 and 24:01:00. Unlikely this would have any more significant effect in practice. While there is a 24:00:00, there is certainly *no* 24:00:00.0001. That would be

Re: 24:00 versus 00:00

2006-02-16 Thread Ed Davies
Markus Kuhn wrote: With the 24-h notation, it is a very useful and well-established convention that 00:00 refers to midnight at the start of a date, while 24:00 refers to midnight at the end of a date. Thus, both today 24:00 and tomorrow 00:00 are fully equivalent representations of the same

Re: 24:00 versus 00:00

2006-02-16 Thread John Cowan
Ed Davies scripsit: If only the 24:00 for end of day notation wasn't in the way we could look at positive leap seconds as just being the result of deeming certain days to be a second longer than most and just use 24:00:00. We wouldn't have to muck with the lengths of any of the hours or

Re: 24:00 versus 00:00

2006-02-16 Thread Warner Losh
From: Markus Kuhn [EMAIL PROTECTED] Subject: Re: 24:00 versus 00:00 Date: Thu, 16 Feb 2006 19:53:22 + Steve Allen wrote on 2006-02-16 19:25 UTC: No reply from an NTP server shall ever represent any point in time between 23:59:60 and 24:00:00 of a UTC day. Minor point, I think

Re: Ambiguous NTP timestamps near leap second

2006-02-16 Thread Rob Seaman
On Feb 16, 2006, at 2:06 PM, Markus Kuhn wrote: While there is a 24:00:00, there is certainly *no* 24:00:00.0001. That would be 00:00:00.0001 instead. Says who? Didn't we just burn a lot of calories discussing whether UTC was a real number or a continuous function? Time does

Re: Ambiguous NTP timestamps near leap second

2006-02-16 Thread Warner Losh
From: Rob Seaman [EMAIL PROTECTED] Subject: Re: [LEAPSECS] Ambiguous NTP timestamps near leap second Date: Thu, 16 Feb 2006 16:30:37 -0700 On Feb 16, 2006, at 2:06 PM, Markus Kuhn wrote: While there is a 24:00:00, there is certainly *no* 24:00:00.0001. That would be

Re: Ambiguous NTP timestamps near leap second

2006-02-16 Thread Rob Seaman
On Feb 16, 2006, at 4:46 PM, Warner Losh wrote:UTC rules state that the time sequence should be23:59:59.7523:59:60.023:59:60.2523:59:60.5023:59:60.7500:00:00.:00:00.25Well, no.  ITU-R-TF.460-4 says nothing whatsoever about the representation of time using sexigesimal notation: "2.2 A

Re: 24:00 versus 00:00

2006-02-16 Thread Clive D.W. Feather
Markus Kuhn said: Writing 24:00 to terminate a time interval at exactly midnight is pretty common practice and is even sanctioned by ISO 8601. See for example the railway timetable on http://en.wikipedia.org/wiki/24-hour_clock where trains arrive at 24:00 but depart at 00:00. Usual UK