Allow alternate spec for time origin: "hours since 2011-03-08T12:00:00Z"

[karlmsmith]

Reported by @AnsleyManke on 9 Mar 2011 19:28 UTC
Hein Zelle reports is for data from GRIB files, served by a THREDDS server,

I'm having trouble accessing a THREDDS (OpenDAP) dataset through
ferret.  We export our GFS data files (GRIB2) through thredds. 
Ferret reads and uses the data just fine, but it gets confused 
about the time axis.  THREDDS specifies it as follows:


time: Array of 32 bit Integers [time = 0..0]

long_name: "forecast time"
units: "hours since 2011-03-08T12:00:00Z"
GRIB_orgReferenceTime: "2011-03-08T12:00:00Z"
GRIB2_significanceOfRTName: "Start of forecast"
_CoordinateAxisType: "Time"


Ferret doesn't seem to like that T in the units string.  It parses
the date part, and ignores the time, leading to a time origin of
2011-03-08 00:00 (!)

---

Creating a NetCDF file with a units string that contains a T, as in
units: "hours since 2011-03-08T12:00:00Z"

and ran it through the CF checker. The checker does not complain about this style of writing the date/time string (though it does return an error if the string has a colon, as in 2011-03-08:12:00:00).

It's a simple matter to allow for this in the Ferret code, and is not prohibited by the CF standard, so change Ferret to allow such date strings.

Migrated-From: http://dunkel.pmel.noaa.gov/trac/ferret/ticket/1806

[karlmsmith]

Comment by @AnsleyManke on 9 Mar 2011 21:57 UTC
Done; change is in tm_break_fmt_date.F