[ntp:questions] Leap second to be introduced in June

Mike S mikes at flatsurface.com
Mon Jan 19 17:27:26 UTC 2015

On 1/19/2015 11:56 AM, William Unruh wrote:
> On 2015-01-19, fm at fr.invalid <fm at fr.invalid> wrote:
>> I am not sure what you mean by "sees", but I cant figure a meaning
>> that would be compatible with the fact that UTC clearly identifies
>> 86401 seconds on the day the leap second occurs.
> If you ask utc how many seconds there are between now, and exactly three
> days ago, it ansers 3*86400 even if one of those days had a leap second.
> Yes of course that leap second occurs on the day, but utc forgets that
> it did.

Just, Wow. That's completely wrong.

> TAI does not as far as I know, have a concept of days. It has seconds.
> If you want to convert those seconds into things like days, months, etc,
> that is up to you.

No, the canonical form of TAI is ydmhms...

> So, if we count utc seconds we have
> 1435733999 1435734000 1435734000 1435734001 ...

Those appear to be POSIX times. They're certainly neither UTC nor TAI.

You keep saying "UTC" when you're talking about POSIX, which naively 
tries to keep both epoch (time since...) and wall (UTC) time, and fails 
miserably since the two are mutually exclusive.

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