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/)]

[Tim Cross <theophilusx@gmail.com>]

In a couple of weeks, I will have some spare time and I am happy to look
at the time related functions in org-mode to see if we can refactor them
to make them a bit clearer and possibly more efficient. I would be
hoping for input from the list as guidance experience has taught me that
date/time stuff can often have some subtle corner cases which are
easily missed.

regards,

Tim

Nicolas Goaziou <mail@nicolasgoaziou.fr> writes:

> Hello,
>
> Allen Li <vianchielfaura@gmail.com> writes:
>
>> 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.
>
> You're right. Using UTC doesn't solve any DST bug, despite what
> I initially thought. I think we just need to remove the whole set of
> changes about UTC in `parse-time-string'. We also need to adapt tests in
> test-org-clock since the same time difference could have different
> meanings depending on the time zone. I can do that later, if no one
> objects. WDYT?n
>
> Refactoring time functions in Org is still useful, though.
>
> Regards,


-- 
Tim Cross