[Python-ideas] High Precision datetime
chris.barker at noaa.gov
Thu May 17 12:49:09 EDT 2018
On Tue, May 15, 2018 at 11:21 AM, Rob Speer <rspeer at luminoso.com> wrote:
> I'm sure that the issue of "what do you call the leap second itself" is
> not the problem that Chris Barker is referring to. The problem with leap
> seconds is that they create unpredictable differences between UTC and real
> elapsed time.
> You can represent a timedelta of exactly 10^8 seconds, but if you add it
> to the current time, what should you get? What UTC time will it be in 10^8
> real-time seconds? You don't know, and neither does anybody else, because
> you don't know how many leap seconds will occur in that time.
indeed -- even if you only care about the past, where you *could* know the
leap seconds -- they are, by their very nature, of second precision --
which means right before leap second occurs, your "time" could be off by up
to a second (or a half second?)
It's kind of like using a carpenter's tape measure to to locate points from
a electron microscope scan :-)
The other issue with leap-seconds is that python's datetime doesn't support
And neither do most date-time libraries.
Christopher Barker, Ph.D.
Emergency Response Division
NOAA/NOS/OR&R (206) 526-6959 voice
7600 Sand Point Way NE (206) 526-6329 fax
Seattle, WA 98115 (206) 526-6317 main reception
Chris.Barker at noaa.gov
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Python-ideas