Re: bug#54764: encode-time: make DST and TIMEZONE fields of the list argument optional ones

[Max Nikulin <manikulin@gmail.com>]

On 09/04/2022 14:52, Paul Eggert wrote:
> 0001-Improve-Org-usage-of-timestamps.patch
> 
> From 094345e10ad45e06f7b32e2f8017592210f43463 Mon Sep 17 00:00:00 2001
> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Sat, 9 Apr 2022 00:17:09 -0700
> Subject: [PATCH] Improve Org usage of timestamps
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
> 
> The main thing is to follow the (encode-time X) convention where
> X’s DST component of nil means standard time, -1 means unknown.

I am marking this thread as a patch for https://updates.orgmode.org
"Use -1 (guess) instead of nil (no) for DST value in encode-time arguments"

 From my point of view the changes quoted below are most important ones 
in the patch and they should be committed to the Org repository. 
Preferably a unit test for time zones should be added for 
`org-parse-time-string'.

I omitted changes to improve code style, they should be applied as well, 
I just consider them as having less priority.

I am in doubt concerning `org-encode-time-1' part.

> diff --git a/lisp/org/ol.el b/lisp/org/ol.el
> index a03d85f618..fe6e97e928 100644
> --- a/lisp/org/ol.el
> +++ b/lisp/org/ol.el
> @@ -1575,9 +1575,7 @@ org-store-link
>  	  (setq link
>  		(format-time-string
>  		 (car org-time-stamp-formats)
> -		 (apply 'encode-time
> -			(list 0 0 0 (nth 1 cd) (nth 0 cd) (nth 2 cd)
> -			      nil nil nil))))
> +		 (encode-time 0 0 0 (nth 1 cd) (nth 0 cd) (nth 2 cd))))
>  	  (org-link-store-props :type "calendar" :date cd)))
>  
>         ((eq major-mode 'w3-mode)
It allows to avoid a pitfall with nil as DST value.

> diff --git a/lisp/org/org-macs.el b/lisp/org/org-macs.el
> index b10725bd52..0916da89ac 100644
> --- a/lisp/org/org-macs.el
> +++ b/lisp/org/org-macs.el
> @@ -1242,7 +1242,7 @@ org-parse-time-string
>  	(string-to-number (match-string 4 s))
>  	(string-to-number (match-string 3 s))
>  	(string-to-number (match-string 2 s))
> -	nil nil nil))
> +	nil -1 nil))

It definitely must be changed in the Org code.

> diff --git a/lisp/org/org.el b/lisp/org/org.el
> index d656a51591..1bceb0f53a 100644
> --- a/lisp/org/org.el
> +++ b/lisp/org/org.el
> @@ -14334,7 +14334,7 @@ org-read-date-analyze
>  	 (setq year (nth 5 org-defdecode))
>  	 (setq org-read-date-analyze-forced-year t))))
>      (setq org-read-date-analyze-futurep futurep)
> -    (list second minute hour day month year)))
> +    (list second minute hour day month year nil -1 nil)))
>  
>  (defvar parse-time-weekdays)
>  (defun org-read-date-get-relative (s today default)

Unsure concerning adding extra elements. I would prefer change of 
`encode-time' in future and a compatibility macro as in the following 
for a while.

Max Nikulin [DRAFT][PATCH] org-encode-time compatibility and convenience 
helper. Mon, 11 Apr 2022 22:22:48 +0700.
https://lsit.orgmode.org/7f4ea652-7d22-fb61-f873-5e92f078c9e6@gmail.com