On Fri, Jan 11, 2013 at 9:00 AM, Aleksandar Jelenak - NOAA Affiliate <[email protected]> wrote:
> Here's the modified proposal for the datetime_iso8601 standard name: ... > String representing date-time information according to the ISO > 8601:2004(E) standard. I think we should NOT adopt a string option for datetime variables. To quote Jonathan Gregory: """ In CF we have always applied the principle that we only add to CF when there is a need to do so, i.e. there is a use-case for something which cannot already be represented in CF """ We already have a way to encode datetimes in CF-netcdf. I believe this proposal resulted from the discussion about adding a more flexible approach to datetimes in the CF Data Model. I think that's a good idea, but separate from what encoding is used in CF-netcdf. ( see my recent note for more detail about the difference between and encoding and a data model ). 1) Having multiple ways to encode the same data in file format adds complication to all client code -- client code would need a way to process both ISO strings and "time_unit since datetime" 2) Any client code that can process ISO strings is likely to need to convert them to a client-specific datetime representation anyway, in order to plot, calculate with, etc them. 3) Any client library that can process ISO strings is very likely to be able to also work with "time_unit since datetime" encoded data anyway -- and it had better, as that encoding is part of the standard anyway. As a result, we would be complicating client code, and getting no new functionality. The one advantage I can see at the moment is that simple, non-CF-aware clients, like ncdump, could easily present a nice human-readable format. But I don't think that is worth the additional complication. -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception [email protected] _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
