On 8/18/2011 6:54 AM, Don Murray wrote:
> Hi John-
>
> On 8/17/11 5:50 PM, John Caron wrote:
>> In March I promised to do something with the "udunits handling of fuzzy
>> time units" email conversation. I now have a preliminary implementation
>> of extended date coordinates. docs are here:
>>
>> http://www.unidata.ucar.edu/software/netcdf-java/CDM/DateTime.html
>>
>> If there's interest, I can propose as a CF convention. Otherwise it can
>> remain a CDM extension.
>
Hi Don:
> Thanks for tackling this. I'm just starting a project with
> non-standard calendars and this will help tremendously.
>
> A couple of comment/questions:
>
> - Why is the calendar field limited to integer types? It seems like
> one could use NcML to change the unit of an existing double time
> coordinate variable to be a calendar unit so it can be handled
> correctly, but then you'd have a scope mismatch.
A calendar field is inherently an integer: what does 1.5 months mean? If
you want to use fractions, you really want to use udunits, which are a
fixed amount of time, and then fractions make sense.
Note that support for non-standard calendars should work for both udunit
and calendar units.
> - Some geophysical datasets use units of millions of years before a
> date, e.g. Myr before 1950-01-01. It would be good to support the
> "before" syntax and also support "yr" as an abbreviation for year.
Ive added "mon" and "yr".
I have to say that "Myr before 1950-01-01" doesnt make much sense to me.
There must be something better to do.
> - perhaps you could support "mon" and "mo" for month as well.
> - "grammer" should be "grammar" ;-)
thakns!
Received on Thu Aug 18 2011 - 15:49:04 BST
