@ChrisBarker-NOAA UTC is, in practical terms, a specification for how to turn TAI (a count of SI seconds since the TAI epoch) into time stamps that are synchronized with the motions of the earth. It uses a combination of the Gregorian calendar and leap seconds to achieve this goal. It does not, strictly speaking, provide for a way to deal with times before the TAI epoch. You have no choice but to assume there are no leap seconds, with an unknown impact (but there were no satellites then, and probably no time sequences long enough with fine-enough resolution to matter).
It's an inversion from where all this started, but we could, as you suggested, call the fully metric calendar **`UTC`** or **`gregorian_utc`**. Such a calendar would have all the characteristics of **`gregorian_metric`** in my previous comment. Here's my objection to that name. I'm concerned that this will lead people to think that they can't use that calendar for anything other than 'UTC times'. This is why I used **`gregorian_utc`** for the other case in earlier versions of this proposal. It was to signal that the time variable contains naively converted UTC time stamps, and shouldn't be used for anything else. -- 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-436005691
