[tz] New Yorker article on David Mills and NTP

[Guy Harris]

On Oct 4, 2022, at 12:55 PM, Paul Gilmartin via tz <tz at iana.org> wrote:

> I'd vote for UT1 for civil time and IT, and TAI otherwise.  Some
> IT organizations have adopted leap smearing.

If "IT" means "information technology", it's a big field, and not all uses of time in it are the same.

Time sindications entered by or shown to users are presumably in hours/minutes/seconds form, possibly with a date in year/month/day form.  For those, there is a choice between UT1, UTC and TAI, all of which, as far as I know, represent time stamps in that form.  In most cases, a system would presumably show, and expect, something in civil time form, although there might be some computing equipment accepting and displaying TAI.

However, there are places in IT where neither UT1, nor UTC, nor TAI, all of which, as far as I know, represent time stamps in forms such as YYYY-MM-DD HH:MM:SS{.fraction}, are used.  Instead, a count of ticks since some particular instant in the past is used, where, for different representations, different things are done at and near the time a leap second occurs, including "do nothing different from any other second".

Those time representations may be used to show civil time (local or UT of some sort) or to show TAI.

They might *also* be used to calculate the time that elapsed between two events, as a (possibly non-integral) number of SI seconds.