Subject: bug#55635: `make-decoded-time' incorrectly sets DST to nil, it should be -1 (guess)

From: Lars Ingebrigtsen <[email-masked]>
Date: Sun, 29 May 2022 15:10:19 +0200

Paul Eggert <[email-masked]> writes:

> With that in mind, here are three suggestions.
>
> 1. decoded-time-dst should return -1, instead of nil, when given a
> 6-element list, since nil means standard time and -1 means DST is
> unknown.

I think that sounds correct.

> 2. make-decoded-time should generate a six-element list unless given a
> DST or ZONE arg.

I don't think we should do this.  Yes, the remaining elements are
nonsensical when talking about intervals, but people rely on that
function to return its documented value.  If somebody wants to do
interval calculations and passes in a DST to make-decoded-time, that's a
classic "well, don't do that" situation.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no