On Thu, May 17, 2012 at 04:01:11PM -0700, Eliot Miranda wrote:
> On Thu, May 17, 2012 at 10:42 AM, Bert Freudenberg <bert at freudenbergs.de>wrote:
> 
> > On 17.05.2012, at 19:29, Eliot Miranda wrote:
> >
> > What is ambiguous about the start of the 20-th century in GMT?
> >
> >
> > Nothing. But Smalltalk epoch was not defined in GMT. It's local time.
> >
> 
> I'm not sure I buy that.   Looking at Smalltalk-80 v2 the California
> timezone was hardwired in.  So I think the epoch was in GMT and e.g. Time
> currentSeconds: #seconds answered the number of seconds from the GMT epoch.

If that were actually true, someone would have said so when they described
the meaning of the Smalltalk epoch. But they did not say so, and no such
definition exists anywhere except in the unsubstantiated opinions and
misconceptions of you, me, and everyone else on this list.

You have illustrated the problem perfectly: "I think the epoch was ..."
is your interpretation of what you think that someone might have intended,
which may or may not correspond with what was actually intended, if in fact
they intended anything at all, which most probably they did not. This is not
an issue that would have been on the forefront of anyone's consideration when
designing a personal computing system for the empowerment of individuals.

>  certainly that's what the Cog VMs answer.  But there's nothing to stop us
> firming up the definition.  1970 is a pretty arbitrary choice of epoch.
>  The start of the 20th century has a certain elegance.

I would have prefered to propose the end of the Mayan calendar as the
more elegant reference point, but unfortunately the definition of this
point in time appears to suffer from some ambiguity also ;-)

>  Even Microsoft have
> a nice epoch (the start of the gregorian calendar IIRC).  Why slavishly
> follow unix when we have something distinctive and hard-wired into the VMs?
>  Why not just define the Smalltalk epoch properly?

Because after more than 10 years of answering questions about this stuff
over and over, it would be really nice to be able to simply refer people
to the relevant Wikipedia page, where the concepts are properly documented
and clearly explained.

I do appreciate the distinctive nature of the Smalltalk epoch, and it can
be retained indefinitely for sentimental and historical reasons. But it
simply is not suitable for use as the basis for time measurement, however
much we might wish it were otherwise.

Dave