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.
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.
- 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.
- perhaps you could support "mon" and "mo" for month as well.
- "grammer" should be "grammar" ;-)
- I don't think the "udunit date grammer" is any more difficult to
understand than the ISO8601 grammar. It's basically the same.
Thanks again for tackling this.
Don
--
Don Murray
NOAA/ESRL/PSD and CIRES
303-497-3596
http://www.esrl.noaa.gov/psd/people/don.murray/
Received on Thu Aug 18 2011 - 06:54:19 BST
