RFC: Time Library 0.1

John Meacham john at repetae.net
Wed Jul 6 17:31:22 EDT 2005


On Wed, Jul 06, 2005 at 11:40:31AM +0100, Tony Finch wrote:
> On Tue, 5 Jul 2005, John Meacham wrote:
> >
> > Also, it would be nice if the LeapSecondTable was not a functional type,
> > but rather something with structure, like a list of (year,offset) pairs.
> 
> That's not sufficient, because leap seconds may (currently) occur at two
> points during the year. If you are interested in accurate absolute time
> over history, then it is also insufficient because before 1972 the offset
> between UTC and TAI was continuously variable, and in the future the rules
> for UTC are likely to change.

Yeah, which is why we need a good TAI type. TAI is defined infinitly far
into the past and future. while UTC disapears before 1972 and we can't
know what intervals future UTC times represent. 

It was declared that leap seconds will only occur at the end of years
from now on, rather than possibly every 6 months. but I wouldn't be
opposed to a more general format since they might charge the rules again
(although that seems unlikely). 

        John 

-- 
John Meacham - ⑆repetae.net⑆john⑈ 


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