On Aug 22, 2011, at 6:36 PM, John Caron wrote: > On 8/22/2011 6:37 AM, Jonathan Gregory wrote: >> Dear Chris >> >>> Perhaps there could be an attribute we could set that says whether we have >>> accounted for leap seconds? With the absence of such an attribute to be >>> presumed as meaning leap seconds have been ignored. >> Perhaps the real-world calendars with and without leap seconds should be >> regarded as two different calendars, since they have different encodings >> (meaning decoding/encoding as YMD HMS<-> time-interval since >> reference-time). >> The "true" real-world calendar is the one with leap seconds. >> >> CF has a calendar >> proleptic_gregorian >> >> A Gregorian calendar extended to dates before 1582-10-15. That is, a >> year is a leap year if either (i) it is divisible by 4 but not by 100 or >> (ii) it is divisible by 400. >> >> What if we clarified this calendar as not having leap seconds? Then it could >> be used for real-world applications for recent dates meaning that it was just >> like the real world except that it doesn't have leap seconds. >> >> Model calendars, which are already idealised wrt length of year, don't have >> leap seconds anyway, I am sure. >> >> Best wishes >> >> Jonathan >> _______________________________________________ >> CF-metadata mailing list >> [email protected] >> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > I agree that a separate calendar is needed if we want to have leap > seconds. I think the common form is UTC (or TAI?). Chris, what does the > satellite community use?
Both UTC and TAI, actually. > > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata Christopher Lynnes Goddard Earth Sciences Data and Information Center, NASA/GSFC 301-614-5185 _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
