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/)]

[Allen Li <vianchielfaura@gmail.com>]

On Wed, Nov 1, 2017 at 9:56 PM, Tim Cross <theophilusx@gmail.com> wrote:
>
> OK, thanks for the additional information. That helps a lot.
>
> We can now narrow down where the issue is.
>
> After having looked (only very casually) at some of the org date/time
> related functions, I think there may be quite a few issues. I'm not
> convinced the root cause is org-2ft converting to UTC, though I think
> that change has probably revealed some of the issues.
>
> There does seem to be some inconsistency or lack of clarity regarding
> some of these operations and it could well be that the switch to using
> UTC is not the correct approach, but just switching back probably isn't
> either What does appear to be required is increased consistency in some
> of these functions or where/how they are used. .

Thanks.  I think I have been harping a bit too hard on org-2ft, but
indeed it seems to be a bit more systemic an issue.

> To correctly fix this, I feel more analysis is warranted. I'm prepared
> to look at this and present a summary and options, but it will have to
> wait until after 21st when I start leave from work. It is a complex area
> and perhaps my skills won't be up to it, but I should at least be able
> to identify the main areas needing attention/decisions.

My initial approach would be to do some refactoring here, especially
among org-2ft, org-matcher-time, and org-parse-time-string, each of
which calls the others in a cycle and each share a part of the logic
for interpreting Org mode timestamps.

I'm not familiar with refactoring FOSS code via mailed patches, nor if
Org maintainers would welcome such patches, but I would be willing to
do some refactoring here.

>
> Whether we should change back to non-UTC for time comparisons in the
> meantime is not something I feel informed enough to make a call. It
> really depends on the daylight savings time related issues affecting
> clock tables and other functionality.  This is probably something core
> org maintainers will need to make a call on.
>
> Tim