[tz] Fractional seconds in zic input
eggert at cs.ucla.edu
Mon Feb 5 05:07:54 UTC 2018
Howard Hinnant wrote:
> If we are to add fractional second support, it should come with a specification of the precision, or precision-range that is supported (e.g. centiseconds, milliseconds, whatever).
zic currently supports only 1-second precision in its output. It accepts any
amount of precision on input, limited only by size of memory, and ignores
Come to think of it, zic should round instead; I'll add that shortly.
It's not clear to me that the zic man page should specify how much precision is
intended to be significant.
> Also, do you anticipate a similar refinement of the “SAVE” quantity?
Yes, I think the current zic man page says that both time-of-day and UT offset
can have fractional seconds. I imagine both could be useful, for the same reason
that to-the-second values were useful before now.
> If such changes to the database are to be made, I would much prefer they be made asap.
We should have tzdb generate both bleeding-edge format (with fractional seconds
and negative DST offsets) and trailing-edge format (without either feature, at
least for now). So you'll be able to test with bleeding-edge if you like. I'll
try to publish a patch to do that soon.
More information about the tz