@Dave-Allured, thank you for your response. As you say the issue can be avoided by using a reference time after 1582, which is fine for end users who can choose the reference time. However, I think the situation for the developers of generic software which uses NetCDF is still unresolved, because they don't have a concrete guidance on how to use these reference times. My proposal would be to add text to the CF Conventions saying how negative years should be interpreted, even if it is something as short as:
"When the year of the reference time is negative, year 0 is not counted in calculations involving this reference time." (or a similar statement), appended to the second paragraph of Section [4.4. Time Coordinate](http://cfconventions.org/cf-conventions/cf-conventions.html#time-coordinate). To answer your question, I write relatively generic software for use with climate observations and climate modeling, which doesn't know what time range is going to be used by the user. I prefer to use Julian date everywhere in my code because it makes it easy to perform any calculations when all time variables have the same reference time. It would be great if NetCDF had a good support for this use case. -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/cf-convention/cf-conventions/issues/298#issuecomment-696450696 This list forwards relevant notifications from Github. It is distinct from cf-metad...@cgd.ucar.edu, although if you do nothing, a subscription to the UCAR list will result in a subscription to this list. To unsubscribe from this list only, send a message to cf-metadata-unsubscribe-requ...@listserv.llnl.gov.
