@ChrisBarker-NOAA @JonathanGregory Again, please back up a step or two and stop thinking in terms of UTC and TAI and don't focus on the time stamps. What we have in a time variable containing fully metric elapsed times is, in essence, TAI with an offset subtracted. It is elapsed time since an epoch, where the values may be smaller than the equivalent TAI elapsed time by the value of the TAI elapsed time at the moment of the **`units`** epoch time stamp. There are numerous ways to get this state of existence, and many of them never need to touch TAI directly.
As a data user, the most important question I have is, "How do I use these values?" Assuming that the data is observational data and that I am a user that cares about sub-minute accuracy, I need to know two things to use the time variable: 1. Are the time values metrical? (What I had been calling fully metric.) (How about that name, @JonathanGregory?) 1. What time system was used for the epoch time stamp in the **`units`** attribute? If the answer to 1) above is no, then I have a third question: - Were the elapsed time values obtained in a well-understood fashion so that I can use them even though they aren't metrical? We are only having this discussion because we spent years not caring about the distinction, and because software packages didn't care about the distinction either. My goal here is to provide a means for data producers to allow data users to answer the 2-3 questions above with the least amount of confusion. -- 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-436038332
