[tz] Proposal for a modern 'Collapsed' Namespace

[Paul_Koning at Dell.com]

On Oct 12, 2012, at 7:33 AM, Robert Elz wrote:

>    Date:        Fri, 12 Oct 2012 12:59:11 +1100
>    From:        Walter <walter.stanish at gmail.com>
>    Message-ID:  <CACwuEiMncemY8tf+aWuDoDumgaSzgAaQCBn5v5+kQp=QaDQbDw at mail.gmail.com>
> ...
>  |  - General accrual of crufty old timezones.
> 
> That's a mistake.  You're making assumptions about the way people use
> the data that are not always correct.   Sure, if all the users ever care
> about is "what is the time now" then zones that are different only wrt
> times in the past seem superfluous - but when you need to look at a
> historical timestamp, which people sometimes do, having the wrong zone
> causes errors.

You almost always need history, because you have stored objects with timestamps on them -- files in directories, for example.  And those timestamps need to be displayed by the rules applicable to that time, not to the rule applicable today.  Otherwise you can't answer questions like "did you create file foo.txt before the noon on April 1, 2001 deadline".

How far back depends on the system.  I work on one where the horizon is 2001; others have horizons that are either closer or farther away.  But many of us -- perhaps all of us -- need some amount of history.

	paul