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Hi Steve, Let me see if I understand what you are doing. It sounds like you are aggregating your data files using a "joinExisting" aggregation on the dummy time variable you added to each dataset. Instead of defining the time values in the dummy time variables, you are defining them in the XML. (Is it just easier that way or is there some other reason?) Back to your main question: THREDDS aggregations don't understand different calendars. However, the CF convention describes how to specify various calendars in a netCDF file. So, by getting the time values and certain attributes correct, you should end up with a 360-day calendar dataset according to CF. Section 4.4.1 "Calendar" in the CF specification details what you'll need with some other good info, if your not up on CF time coordinates, in section 4.4 "Time Coordinates": http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html#calendar http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html#time-coordinate I'm not that familiar with this part of CF and it isn't clear to me how to define your time values. There aren't any examples showing how the 360 day year interacts with the "units" value which according to udunits is a "mixed Gregorian/Julian calendar". The best bet here is probably to post a question on the CF mailing list. You can subscribe to that from the "Discussion" section of the CF site (http://cf-pcmdi.llnl.gov/). One other aggregation note. If your file names indicate the time for that file, you may be able to use a "joinNew" aggregation instead of "joinExisting". You could then use a "dataFormatMark" attribute to extract the run time of each file. Though I guess you'll need to figure out what the time values should be according to CF before proceeding with this. Anyway, more info on "dateFormatMark" in section "Extracting date coordinates from the filename" of the aggregation page: http://www.unidata.ucar.edu/software/netcdf/ncml/v2.2/Aggregation.html Hope this all helps, Ethan > We have some ROMS model results that are based on a 360 day calendar year. > Is there a way to specify this kind of year in THREDDS? We have a file > every three days, 120 files per year. To complicate the issue the files > don't have a time variable in them. > > For now, in the xml file I have specified: > > <variable name="time" shape="time" type="float"> > <attribute name="units" value="hours since 1991-01-01 00:00 UTC"/> > <values start="0.0" increment="73.0"/> > </variable> > > and it is working. To get this to work though I did have to add a dummy > time variable in each data file. > > I specified 73 hours for the increment to make up for the 5 day difference > in calendar years. > > Rich Signell seemed to think that maybe there was a provision for this > sort of thing. If so, can you help me with it? > > Thanks a lot, > > Steve Ticket Details =================== Ticket ID: RNZ-598093 Department: Support THREDDS Priority: High Status: Closed