[tz] JavaScript IANA date/time library, now with support for leap seconds, TAI, TDT

[Kerry Shetline]

On 2021-04-26, at 20:07, Kerry Shetline <kerry at shetline.com> wrote:
> 
> On Mon, 26 Apr 2021 15:06:12 -0600, Paul Gilmartin <PaulGBoulder at aim.com> wrote:
>>> POSIX time is really just UTC without the leap seconds, isn?t it?
>>> 
>> More precisely, POSIX time counts non-leap seconds since 1972-01-01t00:00:00 UTC.
> 
> That would be 1970-01-01T00:00:00 UTC. 1972 is, however, the year that the first official leap second (for POSIX not to count) occurred.

Well, OK… to correct my correction...

I see that official UTC didn’t start until 1972, but POSIX time is 0 seconds at 1970-01-01, which I suppose works as a kind of proleptic UTC. I tend not to think of a count as “starting” at 63,072,010. :-)