[LEAPSECS] Bulletin C and all that

[Warner Losh]

> On Jan 26, 2015, at 9:00 AM, G Ashton <ashtongj at comcast.net> wrote:
> 
> ISO 8601 is the normative definition for date or time representations THAT
> CLAIM CONFORMANCE TO ISO 8601. I don't believe the standard was written with
> a goal of being a general reference work on time and date notation in
> general. So, for example, I wouldn't take their choice of midnight to divide
> days as a statement that everyone who used the Gregorian calendar since 1582
> has also divided the day at midnight.

It all depends on the data that you are using whether the new day starts at midnight
or noon. If you are talking to astronomers before the 20th century, chances are good
it is noon. Civil folks chances are it is midnight. This ambiguity is why insurance companies
say that something runs from 12:01am or 11:59pm or some other time that’s unambiguous.

Warner