Re: [art] Predictable Internet Time

[Joe Touch <[e-mail]>]

On 3/28/2017 8:13 AM, Tony Finch wrote:
> Philip Homburg <[e-mail]> wrote:
>> A few random comments.
> Good comments :-)
>
>> - There are two types of solar time. The actual solar time where the sun is
>> at the highest point at noon, and mean solar time.
> The usual term for the former is "apparent solar time". If you are talking
> about both then it's worth saying the difference between apparent and mean
> solar time is called the equation of time.

Will do.

>
>> - One thing I'd like to add is 'uptime' or more general, monotonic time.
> An interesting discussion re. compatible APIs for elapsed time:
> https://github.com/golang/proposal/blob/master/design/12914-monotonic.md
This is another example of the confusion that results when the time
scale is not clearly indicated or defined. Having Go read the "system
wall clock" is the source of the problem, and this doc explains a
variety of solutions.

I can add a new "monotonic clock" definition that uses an arbitrary
"tick" that is guaranteed to increase between reads and across reboots,
but is not comparable across machines.

>
>> - Another thing worth mentioning explictly is that for the distant future,
>> there is no way to convert between TAI and UTC because future leapsecond are
>> not yet defined. So TAI is good for computing intervals, except if it involves
>> timestamps more than a few months in the future.
> I think "distant future" isn't a very good description for "a few months" :-)
>
> The actual horizon is about 5 - 11 months, just before and just after
> bulletin C is published in January or July
Agreed, but not sure we need that level of detail.

Joe