Hi all:
I assume that someone who uses "months" really wants "calendar months",
which manipulates the calendar fields, rather than using a fixed
duration in seconds. The CDM implements this :
http://www.unidata.ucar.edu/software/netcdf-java/CDM/CalendarDateTime.html
and i think i still have to make a formal proposal to CF for it.
However, concerns about backwards compatibility have scuttled most
attempts to extend datetime handling in CF.
John
On 4/10/2013 11:59 PM, Signell, Richard wrote:
Patrick, Lansing & Co:
I note that the time units for this dataset are:
"units: months since 1901-01-01 00:00:00"
with
"calendar: standard"
In the CF documentation
http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.6/ch04s04.html
it warns about units of "month":
" We recommend that the unit year be used with caution. The Udunits
package defines a year to be exactly 365.242198781 days (the interval
between 2 successive passages of the sun through vernal equinox). It
is not a calendar year. Udunits includes the following definitions for
years: a common_year is 365 days, a leap_year is 366 days, a
Julian_year is 365.25 days, and a Gregorian_year is 365.2425 days.
For similar reasons the unit month, which is defined in udunits.dat to
be exactly year/12, should also be used with caution."
Perhaps the WMS and OPeNDAP service are not handling units of month in
the same way?
-Rich
On Wed, Apr 10, 2013 at 5:45 PM, Lansing Madry <madry@xxxxxxxxxxxxxxxx> wrote:
Hi Patrick,
I pulled down the file via http service and looked at it in ToolsUI.
ToolsUI (perhaps unsurprisingly) gives the "1951-07-16T12:12:04.339Z" value.
I'm not familiar with ferret as an OpenDAP client or viewer, have you heard
from anyone on that front?
Regards,
Lansing Madry
Unidata
Boulder, Colorado
On 4/9/2013 11:08 AM, Patrick Brockmann wrote:
Hi all,
I have a strange behaviour with time dimension values exposed by the
GetCapabilities
and values get from an OPeNDAP access.
Could someone explain me what is the source of the problem ?
http://webportals.ipsl.jussieu.fr/thredds/wms/CARBON/CARBONES_PRIOR_orchidee_hadgem2-es_historical_nosoc_co2_npp_monthly_1951_2004_yearmonmean_3.nc?service=WMS&version=1.3.0&request=GetCapabilities
---> 1951-07-16T12:12:04.339Z, ....
And from the OPeNDAP access with ferret client, I get
ferret
yes? use
"http://webportals.ipsl.jussieu.fr/thredds/dodsC/CARBON/CARBONES_PRIOR_orchidee_hadgem2-es_historical_nosoc_co2_npp_monthly_1951_2004_yearmonmean_3.nc";
yes? sg/t/l=1:10 npp2
GRID GTL2
name axis # pts start end
MYLON LONGITUDE 720mr 0E 0.5W
LAT LATITUDE 360 r 89.75S 89.75N
normal Z
TIME TIME 54 r 16-JUL-1951 12:33 15-JUL-2004 09:01
L T TBOX TBOXLO TSTEP (months)
1> 16-JUL-1951 12:33:59 12 14-JAN-1951 21:39:23 606.4526
2> 15-JUL-1952 18:23:11 12 15-JAN-1952 03:28:35 618.4526
3> 16-JUL-1953 00:12:23 12 14-JAN-1953 09:17:47 630.4526
--> Note the difference between 1951-07-16T12:12:04.339Z and 16-JUL-1951
12:33:59
My TDS version is Version 4.3.15 - 20121218.1126
Regards
Patrick
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