On 8/23/2011 6:13 AM, Lynnes, Christopher S. (GSFC-6102) wrote:
> 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
>>> CF-metadata at cgd.ucar.edu
>>> 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.
Then i would propose adding those two calendars, if they are really
used. OTOH, i dont have an implementation of them, although there are
plans to add to java 8.
Received on Tue Aug 23 2011 - 16:31:19 BST
