RFC: Time Library 0.1

[Ashley Yakeley]

In article <87zmszqafq.fsf at sefirot.ii.uib.no>,
 Ketil Malde <ketil+haskell at ii.uib.no> wrote:

> > Returning a built-in table is worse than useless, as any program 
> > compiled with it will soon break.
> 
> Apparently, that's what the Perl library (libdatetime-leapsecond-perl)
> does.  (It's the only thing I can find on my box that seems to worry
> about leap seconds)
> 
> "break" as in "give slightly inaccurate results".

Well, if you don't mind being off by a second or two, then you don't 
need leap-seconds at all. Otherwise the program you compiled in 2005 
will be wrong in 2010.

> > We could however check for /etc/leapseconds.txt, that might be useful. 
> > But it's not clear what the behaviour on Windows or other platforms 
> > should be.
> 
> Is /etc/leapseconds.txt a standardized file/location at all?

I don't even know if it is.

> > readLeapSecondTable :: FilePath -> IO LeapSecondTable
> 
> It would be nice if it had the ability to fetch the table over the net
> as well, perhaps?

We should at least also (or instead) have 

  parseLeapSecondTable :: String -> Maybe LeapSecondTable

This would parse "leap.sec" files as provided by USNO (unless there's 
some other standard format).

-- 
Ashley Yakeley, Seattle WA