Aleksandar, I support this standard name proposal. I like the restrictions on syntax and use to a sensible subset for scientific applications.
Unlike most standard name proposals, this is more than a simple definition of a physical meaning. You are making a set of technical use specifications, with significant departures from the reference standard ISO 8601. Will there be a reference archive for the particular specifications? Will this reside exclusively in the CF standard name table, or in a new CF chapter or appendix, or something? I think there needs to be something better than "that CF list discussion of January to March 2013". Please be exact in the specification of the reference calendar. Try to eliminate all possible measurement ambiguities. Leap seconds are a problem. There are no leap seconds in the standard calendars currently defined by CF, and I was not able to locate exactly where ISO8601 stands on this issue. I would really hate to see a "Gregorian calendar" or proleptic_gregorian implementation with interval calculations that differ from the CF defined calendars. I suggest a requirement that the calendar attribute be included on all variables using datetime_iso8601. If leap seconds are excluded, then the correct attribute value should be "proleptic_gregorian". You have "four-digit years". Are you explicitly restricting the spec to only years 0000 through 9999? Thank you for working on this! --Dave On Fri, Jan 11, 2013 at 10:00 AM, Aleksandar Jelenak - NOAA Affiliate <[email protected]> wrote: > Dear All: > > Here's the modified proposal for the datetime_iso8601 standard name: > > standard_name: datetime_iso8601 > > Units: N/A > > String representing date-time information according to the ISO > 8601:2004(E) standard. Variables with this standard name cannot serve > as coordinate variables. Date-time information is in the Gregorian > calendar. For dates preceding the Gregorian calendar the date-time > information is in the proleptic Gregorian calendar. Possible date-time > string forms are: > > <datetime> = <date> "T" <time> <timezone> ; > > <date> = YYYY "-" MM "-" DD | YYYY "-" DDD ; > > <time> = hh | hh ":" mm | hh ":" mm ":" ss | hh ":" mm ":" ss "." S > | hh ":" mm ":" ss "," S ; > > <timezone> = "" | "Z" | "+" hh | "+" hh ":" mm | "-" hh | "-" hh ":" mm > > Where: > > * "YYYY" is a four-digit year (0000-9999). > > * "MM" is a two-digit month of the year (01-12). > > * "DD" is a two-digit day of the month (01-31). > > * "DDD" is a three-digit ordinal day of the year (001-366). > > * "hh" is a two-digit hour (00-23). > > * "mm" is a two-digit minute (00-59) > > * "ss" is a two-digit second (00-59). > > * "S" is one or more digits representing a decimal fraction of the > second. > > * The value of any designator when not specified is zero. > > * If <timezone> is ommitted the default value is "Z". > > > -Aleksandar _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
