@JimBiardCics ,@JonathanGregory: I can see two interpretations of the calendar which Jim calls `utc_stamp` and which Jonathan has been calling `gregorian`, in which the calendar is treated as having fixed length days and the time stamps are treated as being UTC. In this calendar, `2 minutes since 2016-12-31 23:59:00` will be treated as `0 minutes since 2017-01-01 00:01:00`. The elapsed time within the calendar system is 120 seconds, the elapsed time between the UTC time stamps in the real world is 121 seconds because of the leap second. So, if we have this data in the CF convention, which do we think is the correct elapsed time? I've seen comments from Jonathan that suggest to me that is should be considered as 120 seconds .... because that is what has been entered in the file. I've also seen comments that appear to imply that 121 seconds should be considered as correct.
I would prefer the first interpretation, as we would then have a CF data file that is internally consistent. I think it would be far better to have information about the mapping between the calendar time stamp and UTC encoded in a separate attribute in order to make it clearer to users what is going on here, and to have a clear distinction between the clean and internally consistent definition of calendar properties (60 seconds per minute, etc) and the messy mapping to the real world. Jim has both though and fought about this approach before, but it still looks like a cleaner solution to me. -- You are receiving this because you commented. Reply to this email directly or view it on GitHub: https://github.com/cf-convention/cf-conventions/issues/148#issuecomment-437061477
