System.Time.Clock Design Issues

[Keean Schupke]

Ashley Yakeley wrote:

>Time turns out to be complicated by nature, and it's not possible to be 
>as simple as we'd like and still be completely correct: there's a 
>trade-off between simplicity and correctness.
>
>I lean towards correctness myself, I think there are ways of managing 
>extra complexity. We might, for instance, be able to separate some of 
>the less-used functions into another module fairly sensibly.
>
>There's also a trade-off between simplicity and usefulness. My earlier 
>message has one idea of where to draw the line, as well as one way of 
>splitting the functionality:
><http://www.haskell.org//pipermail/libraries/2005-January/002930.html>
>
>Simon suggested naming the two modules "System.Time.Clock" and 
>"System.Time.Calendar". These are the issues that seem to be remaining 
>for the "Clock" module:
>
>* Can we assume that gettimeofday always returns UTC rather than TAI 
>time?
>  
>
One question... get timeofday assumes things about the time-system. I 
would be happier
with a 'gettime' call which returns some universal concept of time in an 
SI unit (which for
time is seconds, so microseconds/picoseconds whatever)

I am uncomfortable with introducing non SI notions of time interval like 
hours/minutes
(even days) as these may vary...

I feel conversion into 'familiar; units should be done from this 
universal time... Especially if
anyone wants to write software for the Mars mission!

    Keean.