Re: Bug: org-2ft and/or float-time is wrong [9.1.2 (9.1.2-22-ga2a034-elpaplus @ ~/.emacs.d/elpa/org-plus-contrib-20171023/)]

[Nicolas Goaziou <mail@nicolasgoaziou.fr>]

Hello,

Allen Li <vianchielfaura@gmail.com> writes:

> I guess the relevant bug is
> http://lists.gnu.org/archive/html/emacs-orgmode/2017-07/msg00097.html,

FWIW, this is not the initial bug.

> From what I can glean from the history,
> 112c5ba479d52c3c36de5c7aafd14ab6bc075005 is where things started to go
> wrong.  UTC timezone was added to tests.  From there, a number of
> commits were added to fix regressions.
>
> The problem is that the tests were made to assume UTC timezone and Org
> mode was changed to also use UTC timezone to make the tests pass;
> however, this means that org.el no longer works for non-UTC time
> zones.
>
> That commit's message (112c5ba479d52c3c36de5c7aafd14ab6bc075005) also
> seems suspect.  It claims to be removing DST offset by enforcing UTC.
> That could only be true for people using GMT.  In GMT during DST,
> enforcing UTC would "remove" the DST offset, but that is not true
> anywhere else.
>
> Given my chain of reasoning, the commits following
> 112c5ba479d52c3c36de5c7aafd14ab6bc075005 to fix "regressions" is
> really just converting all of Org mode's timestamps to use the
> "timezone adjusted" Unix timestamps introduced by
> 112c5ba479d52c3c36de5c7aafd14ab6bc075005

IIRC, the point is to remove DST in durations, i.e., in the difference
between two dates. One way to do that is to assume UTC in both start end
end date. Most of the commits are about making sure UTC is used whenever
two Org dates are to be used in a duration computation, and nowhere
else.

I think the change to org-2ft was a side-effect, since it is indirectly
used is a duration.

Regards,

-- 
Nicolas Goaziou                                                0x80A93738