On 2015-01-18, Mike S <mi...@flatsurface.com> wrote: > On 1/13/2015 11:46 PM, William Unruh wrote: > >> That is a translation from seconds to ymdhms. The problem is not there. >> it is in the UTC seconds. >> In UTC one second disappears after the leap second, but not before or >> during. Thus UTC seconds numbering is simply disconinuous (jumps back) . > > UTC jumps neither forward nor backwards. UTC simply allows minutes of > 59, 60 or 61 seconds. There is NO discontinuity. The canonical form of > UTC (and TAI) is ymdhms.
UTC always has 86400 seconds per year. > > TF.460 describes very clearly how UTC is enumerated. "A positive > leap-second begins at 23h 59m 60s and ends at 0h 0m 0s of the first day > of the following month. In the case of a negative leap-second, 23h 59m > 58s will be followed one second later by 0h 0m 0s of the first day of > the following month" > > http://www.itu.int/rec/R-REC-TF.460-6-200202-I/en B International atomic time (TAI) The international reference scale of atomic time (TAI), based on the second (SI), as realized on the rotating geoid, is formed by the BIPM on the basis of clock data supplied by cooperating establishments. It is in the form of a continuous scale, e.g. in days, hours, minutes and seconds from the origin 1 January 1958 (adopted by the CGPM 1971). Note: It is in the form of a continuous scale. C Coordinated universal time (UTC) UTC is the time-scale maintained by the BIPM, with assistance from the IERS, which forms the basis of a coordinated dissemination of standard frequencies and time signals. It corresponds exactly in rate with TAI but differs from it by an integer number of seconds. The UTC scale is adjusted by the insertion or deletion of seconds (positive or negative leapseconds) to ensure approximate agreement with UT1. Note UTC differs from TAI by an interger number of seconds, AND that integer changes with the leap second. Ie, it cannot be continuous if TAI is continuous. > > The issue you're describing is an issue with POSIX time, which doesn't > handle leap seconds. _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
