On 03/01/2017 18:03, Cyrus Daboo wrote:
Hi Phillip,
--On January 3, 2017 at 12:42:42 PM -0500 Phillip Hallam-Baker
<phill@xxxxxxxxxxxxxxx> wrote:
1) TAI: Use this and only this for any and all purposes that involve
recording the time an event took place. Including forensic and
scientific
purposes.
2) PIT: Use this for inter-machine communications. It may also be
used to
present TAI in a human readable form because the mapping from TAI to PIT
is fixed.
3) Local Time Zones: For human display purposes
Please note that local time is needed not just for human display
purposes but also for handling recurring events that are "anchored" to
a local time. e.g., you want your thermostat to turn on at 6pm local
time every day, but that has to account for daylight saving time
changes etc. Thus when defining future data/time values, often (local
time & time zone id) is required and must be part of the data
interchange between devices. Thus the need to keep devices up to date
with time zone changes (which was the primary impetus for the tzdist
RFC7808 work).
Only the UI needs the TZ information, the machine can operate just fine
with any timescale. That is you present the time in local time, but
operate in global time, and this is definitely an application that will
not care about leap seconds.
- Stewart