[ferret_users] Proleptic Gregorian Calendars overridden

[Russ Fiedler <russell.fiedler@xxxxxxxx>]

Hi,


I've got a time series  with the time definition


    double time(time) ;
        time:long_name = "time" ;
        time:cartesian_axis = "T" ;
        time:calendar_type = "PROLEPTIC_GREGORIAN" ;
        time:calendar = "PROLEPTIC_GREGORIAN" ;
        time:bounds = "time_bounds" ;
        time:units = "days since 0001-01-01 00:00:01" ;

Now, Ferret is a bit odd in its behaviour with respect to 
standard/gregorian calendars in that it uses the Proleptic Gregorian 
calendar EXCEPT when the starting date

is 0001-jan-01 when it and times are after 1582 when reverts to the cf 
compliant mixed gregorian/julian.


https://www.pmel.noaa.gov/maillists/tmap/ferret_users/fu_2005/msg00625.html

https://ferret.pmel.noaa.gov/Ferret/documentation/users-guide/Grids-Regions/GRIDS#_VPINDEXENTRY_634

http://cfconventions.org/Data/cf-conventions/cf-conventions-1.7/cf-conventions.html#calendar


I can handle the odd behaviour for legacy reasons but, surely, if I 
specify PROLEPTIC_GREGORIAN Ferret should respect that attribute and not 
muck about with the calendar.

Al the least I'd like a way to turn off this behaviour.

Maybe something like


SET  AXIS/CF_COMPLIANT_CALENDAR taxis



to get proper axis specifications no matter what (or if the 
"Conventions" attribute  "CF-X.X" is found then do it according to that 
convention).


Cheers,

Russ