Re: [PATCH] org-test: Fix zone-dependent miscalculation of days of week

[Kyle Meyer <kyle@kyleam.com>]

[ Sorry, I somehow managed to drop the References and In-Reply-to
  headers from my previous reply.  I'll include that message again here
  along with some examples. ]

Ihor Radchenko writes:

> I suspect that the failures are because of your timezone.

Yes, that matches my conclusion too and was what I was trying to convey
in the commit message.

> If my guess is right, there will always be some timezone where a given
> number seconds from epoch is a different day...
> I am not sure how to address this problem.

How about my patch?  Notice that format-time-string is invoked with ZONE
set to t so that TIME is always taken as UTC.

Examples
--------

;;; locale en_US.UTF-8
;; local time zone (Japan in this demo)
(format-time-string "%A %T %z" 259200) => "Sunday 09:00:00 +0900"
;; force UTC
(format-time-string "%A %T %z" 259200 t) => "Sunday 00:00:00 +0000"

;; locale de_BE.UTF-8
;; local time zone
(format-time-string "%A %T %z" 259200) => "Sonntag 09:00:00 +0900"
;; force UTC
(format-time-string "%A %T %z" 259200 t) => "Sonntag 00:00:00 +0000"