From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alan Schmitt <alan.schmitt@polytechnique.org>
Subject: Re: babel and computing a number of months
Date: Mon, 02 Jun 2014 14:06:10 +0200
Message-ID: <m2r4371pot.fsf@polytechnique.org>
References: <m2wqcz3h97.fsf@polytechnique.org> <87d2erpw3l.fsf@gmail.com>
Mime-Version: 1.0
Content-Type: text/plain
Return-path: <emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org>
Received: from eggs.gnu.org ([2001:4830:134:3::10]:41653)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <alan.schmitt@polytechnique.org>) id 1WrR0L-0007j5-BX
	for emacs-orgmode@gnu.org; Mon, 02 Jun 2014 08:06:23 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <alan.schmitt@polytechnique.org>) id 1WrR0D-0001RI-Jv
	for emacs-orgmode@gnu.org; Mon, 02 Jun 2014 08:06:17 -0400
Received: from mail3-relais-sop.national.inria.fr ([192.134.164.104]:62043)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <alan.schmitt@polytechnique.org>) id 1WrR0D-0001Qo-ED
	for emacs-orgmode@gnu.org; Mon, 02 Jun 2014 08:06:09 -0400
In-Reply-To: <87d2erpw3l.fsf@gmail.com> (Alexis's message of "Mon, 02 Jun 2014
	18:13:50 +1000")
List-Id: "General discussions about Org-mode." <emacs-orgmode.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/emacs-orgmode>,
	<mailto:emacs-orgmode-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/archive/html/emacs-orgmode>
List-Post: <mailto:emacs-orgmode@gnu.org>
List-Help: <mailto:emacs-orgmode-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/emacs-orgmode>,
	<mailto:emacs-orgmode-request@gnu.org?subject=subscribe>
Errors-To: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org
Sender: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org
To: Alexis <flexibeast@gmail.com>
Cc: emacs-orgmode <emacs-orgmode@gnu.org>

On 2014-06-02 10:13, Alexis <flexibeast@gmail.com> writes:

> Alan Schmitt writes:
>
>> I need to work with dates for some code/scripts I'm writing in a
>> document making heavy usage of source blocks and babel evaluation. The
>> good news is that I have access to many programming languages, so the
>> bad news is I don't know which one to choose. The problem I want to
>> solve is the following: I want to compute the number of months between
>> march 1st, 2014, and the beginning of the current month (so right now
>> it's 3, but on may 31st it was 2). Is there an easy way to do it in a
>> babel supported language?
>
> How about Perl with either DateTime::Moonpig:
>
> https://metacpan.org/pod/DateTime::Moonpig
>
> or Time::Piece:
>
> https://metacpan.org/pod/Time::Piece

Thank you for the suggestion. I finally did a very hackish simple
solution:
#+begin_src emacs-lisp
(defun nbmonthssince (year month)
  (let* ((tm (decode-time))
	 (cmonth (nth 4 tm))
	 (cyear (nth 5 tm)))
     (+ (* 12 (- cyear year)) (- cmonth month))))
#+end_src

Alan