From mboxrd@z Thu Jan  1 00:00:00 1970
From: Allen Li <vianchielfaura@gmail.com>
Subject: 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/)]
Date: Wed, 1 Nov 2017 17:10:21 -0700
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To: Nicolas Goaziou <mail@nicolasgoaziou.fr>
Cc: emacs-orgmode@gnu.org

On Wed, Nov 1, 2017 at 1:55 PM, Nicolas Goaziou <mail@nicolasgoaziou.fr> wrote:
>
> 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.

Alas, I still can't seem to find the original DST bug.  I'm not sure
using UTC solves DST problems.

For example, in the timezone America/Los_Angeles,

<2017-11-05 01:00:00> -> <2017-11-05 04:00:00> = 4 hours
<2017-10-10 01:00:00> -> <2017-10-10 04:00:00> = 3 hours
<2017-03-12 01:00:00> -> <2017-03-12 04:00:00> = 2 hour

This is what Emacs gives me using the default time zone

<2017-11-05 01:00:00> -> <2017-11-05 04:00:00> = 4 hours
<2017-10-10 01:00:00> -> <2017-10-10 04:00:00> = 3 hours
<2017-03-12 01:00:00> -> <2017-03-12 04:00:00> = 2 hour

This is what Emacs gives me using UTC

<2017-11-05 01:00:00> -> <2017-11-05 04:00:00> = 3 hours
<2017-10-10 01:00:00> -> <2017-10-10 04:00:00> = 3 hours
<2017-03-12 01:00:00> -> <2017-03-12 04:00:00> = 3 hours

Using UTC seems strictly wrong to me.

>
> I think the change to org-2ft was a side-effect, since it is indirectly
> used is a duration.
>
> Regards,
>
> --
> Nicolas Goaziou                                                0x80A93738